If you were me?

Wow, what great questions!  

Air conditioning varies a lot with the venue.

Places in the far north will have at least minimal heat but perhaps not air conditioning. Places in the far south are fairly likely to be airconditioned but perhaps not heated.

In the vast middle, public schools and an awful lot of unis will have no climate control at all. I've taught uni classes in a greatcoat, scarf, and gloves. In the Summer you'll throw off more sweat than a James Brown concert. Higher-end private schools tend to be fully airconditioned; low-life schools will have at best a fan in the summer and nothing in the winter. Even when there is airconditioning it's often just barely or not quite; the Chinese attitude to airconditioning seems to be "a little goes a long way."

Corporate classes will keep you nice and comfy at all times. They got indoor outhouses- with seats- and everything!

The Chinese are conditioned to not complain or make waves no matter how miserable they may be. They seem incredibly highly tolerant of both very hot and very cold temperatures. They'll be utterly aghast to find that you are not so conditioned.

Cheese: depends on geography. The Chinese don't care much for cheese except a bit on pizza, so its availability is a function of the size/wealth of your foreigner community. Small towns will only give you a puzzled look after you express a desire to eat spoiled milk on what otherwise seems to be a perfectly good ham sandwich. Medium towns and up will have sliced sandwich cheese and a beast called "breakfast cheese" (slightly sweetened cream cheese) in larger supermarkets. Larger towns will have a foreign-owned supermarket (Wal-Mart, Carrefour, Auchan, Metro, etc.) that will offer the above plus a small selection of Australian, New Zealand, European, and/or American cheeses. Really big cities with zillions of foreigners (Beijing, Shanghai, Shenzhen) will have expensive upscale grocery shops featuring cheese counters that would rival some in Europe. I've seen a few surprises...whole wheels of gouda on display in bakeries in otherwise total bohunk cities...but these are isolated and unpredictable.
Cheese is not especially cheap or widespread, no matter what you find.

A quick comment on the visa talk - not having a Z visa does not exclude the possibility of getting a residence permit! Practically everyone at my school came on F or L visas and within 3 weeks of starting had those converted by the school. Can't say that happens everywhere, or is common, but its certainly possible...

It is.
Not technically legal (at least not at one time), but often possible if your school has good connections. Given the option, it's probably still best to arrive with the Z or residence permit clutched tightly in your kung-fu grip if you can.

The visa rules are being/have been streamlined some. It's all changing so much and so fast that it's hard to tell what the hell they want from us anymore.

This visa talk is confusing, the types and the legalities.  As a basic principle, I prefer not to break the law.  Could someone tell me what the different visa types are exactly?  I gather that the Z visa is the type I'll need to work legally.  Can it be obtained without fully committing to a school?  If not, what do I do if I get to China, and see that the school was not as advertised?  Will my visa be tied to that school, and thus I'd legally have to complete my contract with them before becoming a free agent.  This is the exact situation I hope to avoid.

I can't thank you guys enough for your help.

Up north the classrooms are heated in the winter and we have air conditioner's in our classrooms at my University.  Down south - the classrooms are not heated - and that is even worse than no air conditioning.  I dern near froze to death last year - Wore a down coat, gloves scarf and hat while teaching - still froze.  Bought a small electric heater and stood beside it - still dern near froze.  Up here, I had to take my sweater off while teaching as the classroom was so warm.   

I think air conditioners are at a premium at schools here.  They might have one in the teacher's room or offices but not in the classrooms.  Good question to ask of a potential school.

Cheese.  METRO,  Parkson's, Mycal all have cheese (and fresh butter),  - all kinds of cheese, from Australia, Europe, Italy etc.  Don't buy Chinese cheese as it looks and tastes like rubber.  I bought fresh ground Italian Parmesan cheese at Metro.  Much better than Kraft Parmesan which is readily available.  You can get Brie, Gouda, Aged Cheddar etc here easily.  Don't know about the small towns but in Dalian, Beijing, Shanghai, Wuxi, Suzhou etc it is easily found.

I know what you mean about rubber cheese.  The local Korean processed variety doesn't even melt under direct heat, and has no recognizable flavor.  If I can find imported cheese, even if it is expensive, I'll be happy.  Also thanks to all for the input on climate control in the classrooms.  It is definately something to consider.

There is so much to consider: public or private, the frozen north or the sweltering south, huge cities or just very big cities.  My head is starting to spin.

Re the visas:

The visa you obtain before arriving in China is only to get you through immigration and into the country. It has nothing much to do with living here (the exception may be the F Visa - I'm really not sure about that one, having had no experience with it).

A Z Visa is issued to a prospective teacher with a letter of offer to work in a school authorised to hire Foreign Experts. You don't need to have signed a contract before arrival to obtain this - just a written acceptance of the offer (you can still change your mind about signing the contract when you arrive if it isn't as advertised and acceptable to you - and you still have your Z Visa) is sufficient for the school to issue the relevant documents.

Once you arrive you surrender your passport, submit to a medical, hand over your photos and wait somewhere between a week and amonth for it to be returned with a shiny new Residency Permit. That's what makes you legal to live here. You should also be presented with your Foreign Expert Certificate - which is effectively your working permit. Said Residency permit and Foreign Expert Certificate can be renewed upon expiry without you leaving the country, regardless of whether you are renewing a contract with your original employer or moving on to greener pastures. If you're moving on you should have a letter of release from your original employer stating that you have completed the contract and have been offically released to a new employer.

I know from first-hand experience that in Heilongjiang it is damn near impossible to have a Resdiency Permit issued without having the Z Visa (for new arrivals) or a current and clean but expiring Residency Permit. They can't convert a Z L or an F visa.

This is not true in Guangdong. It is common practice here to change from an L or and F entry visa to a residency permit (also from first-hand experience). Here it also seems that a Foreign Expert Certificate is not so popular, rather an Alien Emplyment Permit. Government Schools seem to be the major providers of the FE certificate, and most teachers (technically "trainers") are working on Alien Employment Permits.

I've also just learned that (here in Guangdong and I think in other places as well) that a Residency Permit cannot be easily cancelled by the employer - only the FE certificate or the Alien Employment Permit can be cancelled. In any case, in order for a Residency Permit to be cancelled or revoked the original document in your passport needs to be stamped as cancelled. If that hasn't happened your Residency Permit is valid until the expiry date.

Wow, n-Dave gave an excellent recap of the situation... One sentence may have a typo, though...he may have meant to say "They can't convert an L or an F visa."...

The types of visa are:

L: Tourist visa. Usually shorter-term. Can only stay in hotels. Illegal to work.

F: Business visa. Usually medium- to long-term. Can only stay in hotels or officially-designated housing. Can work for a foreign company, but not a Chinese one. (Note that nearly all "foreign-owned" schools are in fact registered as Chinese companies...)

Z: Work visa. Usually long-term. Permits one to enter China, then rent an apartment and start a job long enough to convert to a Residence Permit.

Residence Permit: Usually one year in duration; may be an academic year rather than a calendar year- this is tied to your contract. This permit conveys full legal permission to live and work in China. If you don't have this, and are not in process of getting one, you are an illegal migrant worker in an authoritarian state. Any school that tells you differently is lying to you for their own enrichment.

There are other visas for particular classes of people (students, diplomats, journalists, airline workers, etc.) but these usually don't interest prospective teachers.

Don't feel bad if you're confused. WE'RE confused. Many of the schools are confused, especially newer ones just beginning to work with foreign teachers. A surprising number of the very officials and police officers who supposedly administer these visas are confused, too. Different provinces, sometimes even different cities, can have different rules regarding visas. And beyond that, schools with good connections in the right Bureaus can quite often easily do things that the letter of the law says are impossible.
So, welcome to Club Confusion... 

One point in particular causes massive confusion. Dave said it, but I'll say it again:
A visa- ANY visa- only gives you permission to enter the country, and carries a requirement to exit China before it expires. Once you have a Residence Permit, visas are irrelevant and not needed. Your expiry date is now the date of the Permit, not the Z visa. The only time you may ever need a visa, once you have the Permit, is if you leave mainland China and then wish to re-enter. Most Permits today automatically come with re-entry privileges; if not, these are easy and inexpensive to obtain. If you ever leave China temporarily, even to go to Hong Kong or Macao, be sure you have re-entry privileges before you leave.

One last point: Yes, many teachers do stay and work here illegally on F and even L visas. A fair number of them get away with it. Many of them, and the schools they work for, will tell you it's fine. Please don't let this fool you: YOU ARE RUNNING A VERY REAL RISK OF SUBSTANTIAL PENALTY, DETENTION, DEPORTATION, AND EVEN JAIL TIME IF YOU DO THIS. This course is absolutely NOT recommended.

Heat in winter?  Body heat and whatever clothing, heating accessories you can carry to the classroom.  Students will be wearing gloves, scarves, winter jackets in class even while taking notes. 

Air in summer?  Open the window (or close it) turn on the ceiling fans and chill out.  Not a lot of energy on some days due to the heat, especially come afternoon classes.

This is in ChangZhou, south of the Yangtze River.

Of course I have air and heat in the apartment.  Students do not have air or heat in their dorms.

As for visas - listen VERY carefully to Raoul.  No exceptions.  None.  Be happy, be safe!

Heat in winter - up the far north we're taken well care of. Apartments and classes all have radiators and the rooms are usually a pleasant 22C and the higher up you are in an apartment, the warmer it is. I'm on the second floor and have large radiators in every room, winter inside was usually warm. Kcannuck's on the fourth floor and has smaller radiators - her apartment was too hot at times.

If you are coming out east, as both Raoul and Eagle mentioned, you will be real lucky to get either heat or air-conditioning. My first two schools, one private and one college had me teaching in mitts in the winter and actually dripping sweat in the summer (which can start as early as the end of April). I think most training centres have heat and A/C but it comes at the cost of more hours to work 

Heating - In some cases it's more comfortable to be farther north in winter. In Hunan, Changsha (just south of the Yangtze) winter is not all that cold. Barely below freezing at anytime but it feels very cold. The buildings are all built for the summer heat and there are no radiators or central air. the buildings are made of concrete and hold no heat. Often on a winter day we will put more clothes on inside than outside. We use foot stoves here to keep warm. This is when it is helpful to have 70+ students crammed into a classroom as they are all little ovens that keep the teacher warm. People will always keep their windows open here for freash air regardless of the temperature, though in Changsha fresh air doesn't exsit. Doing anything outside is very comfortable but inside is cold and you may be cooking with a winter jacket on.

I find the Mainland cheddar (actually made in HK) which has been available in both cities I've been in so far (Dalian and Wuhan) to be pretty decent - the mature stuff is similar to your average UK supermarket mature cheddar.  Of course, it's pretty (relatively) pricey, and as Mrs CD doesn't like it, I don't buy it all that often...

I was pleasantly surprised to find that in Yunnan, because they are non-Han, they make their own local cheese which is a bit like a Halloumi.

The Yunnan cheese was lovely, best had grilled directly on cookstove at 2600 masl with a couple of French backpackers, two Americans, an Aussi and moi this Spring vacation.

Hello bambam---are you in Korea?

I spent 5 years back and forth between the 2...I;d get tired of one and move bak etc etc....

Web and Wall St are basically like Direct English in ROK or Aeon in Japan which Im sure you know of....Although the Chinese won't study English at 6 in the morning as the crazy Koreans will.

Where to go is a toughie of course.I tend to think people like China or they dont no matter where they land.   No accounting for taste though---example I loathe Dalian which is a popular choice for nany and I loved Shenyang which most see as a cesspool.
I also liked the small towns I lived in. A nice middle size city is Shaoxing which is an hour from Hangzhou...

Now to the important mqtter----cheese.   Even smallish towns will have a supermarket big enough to have a Western section--I used to NZ cheese which is fine.and of course there is pizza but it is mostly chains...


It really is a change and a half form Korea though---and if you like to read buy books before departure---lots of them..good luck