Hey Boston, You're in for some fun. Harbin is beautiful this time of year. I lived there (or thereabouts) for a bout a year and really enjoyed it.
Some cool places:
Hamamas Kofi Haus: Hamamas is run by a Papua New Guinean guy called Ronnie and his Chinese wife. It's a small, casual & very popular coffee shop. Big-assed mugs of brewed coffee 12RMB & half-priced refills. Decent cappucino, latte and milkshakes. Great hamburgers, sandwiches (on real bread) and subs. The have a smoked chicken and salad sub that's worth a plane ticket to Harbin. There's also a desert-bar to die for. The staff speak good English, it's no smoking inside and there's a great selection of English books to keep you entertained. It's a pretty good place to meet the local laowai contingent and some friendly locals, too. Say Hi! to Ronnie (you'll know him when you see him) and tell him Aussie Dave sent you. He'll smile and tell you you're welcome and charge you extra!
It's located right near Harbin Institute of Technology (HIT HaGongDa 哈工大) and the computer market (jianghua guangchang 教化广场)
The address is 2/104 Mu Gong Jie (木工街2号104室) Phone number: 0451-88581660
Most of the cabs know MuGongJie - call the shop from the cab and get them to tell the driver if you have trouble.
The computer market is also a great place for anything electrical. (jianghua guangchang 教化广场)
Harbin has a great central walking street - Zhongyang dajie (中央大街) in the downtown daoli district. The south end has the Holiday Inn Hotel with a great sports bar and the best western brekky in town (not the cheapest). The north end has the Songhua River and a Walmart. Lots of good shopping in between.
At the river end is Zhong Xia Video & Audio shop (9 Zhongyi St - just near the intersection with Zhongyang dajie) Zhong Xia is the owner, speaks good English and has the best selection of DVD's in town. If she hasn't got it she'll get it. Phone 139 4517 0327 Chinese address: 道里区中医街9号
Lone Traveller probably has the best info on the nightlife...