This wiki is trying to be a complete free worldwide travel guide. Coverage of China is, to say the least, spotty. I contribute quite a lot there and would encourage others to do likewise.
Recently I've edited the section of their China guide on working here. Anyone care to comment on that?
http://wikitravel.org/en/China#WorkSee also the general page on teaching English as a travel strategy:
http://wikitravel.org/en/Teaching_English