Get a teaching degree first!
Mistakes and problems could be avoided if teachers coming to Thailand held a teaching degree. Many people think they are teachers of anything because they come from an English-speaking country. Thailand is changing its teaching requirements from no degrees in education to degrees in education needed. If you want a great teaching position in Thailand then do the following:
A. Pick up a teaching degree in education from your home country.
B. Apply for a job via a good job services program.
C. Come to Thailand qualified with at least 3 years of teaching experience.
If you follow these steps then you can land a wonderful job in one of the many international schools. Do your homework and check out the international school before you sign a contract. Some of the lower rating international schools pay very little but expect a great deal of work. If the school is decent and trustworthy they will tell you the starting salary and all benefits upfront. The ones that do not tell you the salary upfront are usually low paying and not worth your time. Working in a Thai school can be very satisfying and rewarding as long as money is not an issue.
Good Luck!
Tom