I think its going to depend on what age level and subject you are teaching.
If you haven't taught before, even with that MA....well, I'd try to find a course, even a short cheapy is better than nothing.
It seem like the "New Interchange" and "Passages" series (Jack Williams) is popular in Thailand.
I teach young 'uns and focus quite a bit on Phonics....I find Up and Away to be the best series for this.
One thing...If you're outside of Bangkok you'll want to bring the books with you as access is very difficult outside Bangkok.
There are a lot of very experienced teachers on the forum so you should get some good information. It's a long weekend here so maybe tomorrow will bring you some better response. :smile: