I'd add one thing to Robin's advice:

Try to avoid apartments that are owned by your school, especially if the school is really "owned" by a western entity.

I ran into this situation last summer in Thailand at a high school. Get this--the school offered to pay me 35,000 Baht a month (about 850 USD), but I had to pay for food, visas, housing, electricity, and laundry. The apartment was a 5,000-baht-a-month dump, wasn't furnished, and also required a deposit of 15,000 baht (about 375 USD).

Come to find out later in the interview, the school was "controlled" by a corporate outfit based in Australia. The school wasn't autonomous. On top of this, the apartment was owned by the same group who controlled the school, as was the canteen, laundromat, and whatnot. It reminded me of those old mining towns back in West Virginia during the early 1900s. The mining company owned the mine, the housing, even the grocery stores. The workers got reamed in those places, and I didn't want to end up like that.

Just before giving the school the "not thanks", I calculated that I would have been paying out nearly 15,000 baht a month to the "company" and taking home maybe 20,000 a month out of that 35,000. What a rip this would have been. Plus, at that particular school, I would have been teaching 60-80 high school students per class. What a lot of fun that would have been.

I BELIEVE this high school was also a government school as well, although it was "controlled" by this Australian company.