You couldn't pay me enough to live in China, especially Beijing with all the pollution. Unless you are completely desp and face unemployment, I'd take the offer to work at the Canadian School for a year or two. Just bring lots of pocket masks and learn Chinese. Make the most of it since its getting the most of you.

You'll first want to get your Category 1 certificate. You can do that online. I think it will cost you a few hundred bucks though. Its easier if you are teaching or going to be teaching an IB history course as it takes some time to get your head around the curriculum (Paper 1, Paper 2, HL/SL, Route One/Route Two, Internal/External Assessment etc). I've only been doing it a couple years, but learning the way the course is organized can be a headache for a newbie.

Hodder is really good for IB History, Paper One. I am currently using it to cover the Arab-Israeli conflict. Lots of sources.