To teach at any of the top-tier schools you must have a university degree AND the TESOL cert, as well as a criminal background check from your home country. This is the law. Vietnam has some of the strictest requirements in Asia. Without these documents, you'll be limited to working at the lower-end schools, with lower pay, little support, and the possibility of delayed wages.

Right now demand is quite high for teachers in Hanoi. Don't worry about the degree, but your newbie status means your are going to have to take the less-desirable jobs at nights and on weekends. But given that many teachers don't stick around Vietnam for very long (don't ask me why) you will get some better offer if you take your job seriously. For pay you should look at about 13-15$ for a newbie right now and once you have experience and contacts that will go up quickly. PM when your in Hanoi and I can help you line up some interviews to get you started.

Stoss

Get you police check before you come. Most countries it's quite easy and fast. From abroad it's much more difficult.

Agreed with Stoss about demand and the wage thing. I came to Vietnam as an experienced teacher having signed a year contract already, and I still have the "less desirable" job - 4 classes of young learners each day Saturday and Sunday, and night classes 3 times a week. I'm not really sure how I would do it if I were a 1st time teacher. Although I've heard that after you've put in some time you can change your timetable.

I know of some people who got some gig teaching only uni students during the week for really good pay, so you could always do the part-time thing (no major commitment) and then try to sidle into one of those jobs with some experience.