I just met this guy who was living out in western China for a little while and he relayed a horror story about teaching.

He's English and before he came here he knew little about China and was trying to find a good place to teach. He didn't really have the best idea about where to look, but eventually he stumbled upon a little Chinese company helping foreigners get teaching jobs (you can see this is a disaster waiting to happen).

Anyway, they aren't very helpful and are really stubborn about the payment. Finally he agrees figuring "hey, i'm not going for the money anyway." When he arrives they tell him that they'll give him housing and pay for his airfare at the end of the contract (even though he was supposed to get half right away). Then it turns out that he's not working at one school, but instead they're shipping him to a dozen all over the city each week. Basically they worked out deals with tons of places and are cashing in on him big time. He was only getting 2000 RMB a month and working 22 class hours. 

Once he found out what the going rate was he got into a big fight with them, but managed to leave the country and come back in on a different visa. I think the company didn't want to make a big fuss because they were doing some illegal things anyway.

So, sometimes you have to learn about China the hard way.