I've worked in a number of countries and would suggest that you contact the HR/personel/recruitment departments of a couple of schools in the country you fancy going to and ask them - they should know! Alternatively, why not take a look on the relevant Embassy/consulate websites? They too should know.
The rest of us are operating on personal experience, hearsay and rumour.
I would also recommend working for a school that handles, and pays for, the legal issues such as visas and work permits for you.