I've been living in Hanoi, Vietnam and teaching english for the past 8 months. Jobs are plentiful, the money is fantastic and the chicks are bangin'. There are hundreds of english schools over here. A handful are of a high quality. They pay the best, but they're pretty picky about who they hire. There's a handful at the bottom end who are dodgy as all hell and should be avoided, but the bulk are well run, friendly outfits. There's so much work that there's no need to hook up a job before you get here. For a while, I was only working 15 hours a week, starting at 5.30 pm and banking about $1000US a month. Realistically, you can live off half that. If you work a real 40 hour week, you'll be making serious bank.
A TEFL/TESOL cert helps to get work, having a degree of any kind is better, but having experience wins. Realistically, most schools don't care what qualifications you actually have, they just want you to put good stuff on your CV so they can tell the students that you're super qualified. If they ask for proof of qualifications you don't have, just tell them you don't have it with you and put it off until they give you up or you quit and find another job. Works for me.
If anyone's thinking about coming here, check out The New Hanoian