Hey Victoria,

One thing to decide first is: Do you see teaching as a long-term career for you, or do you just want to spend a year or two abroad and then move on to something else?

If teaching is your career, then AMonk's advice to get a degree in Education and a state teaching certificate is spot on. This will serve you well no matter where you choose to live and work.

If you're specifically considering TEFL/TESL as your career, then you really should find a school that offers that degree/certification. If you're really ambitious in this field, a Master's degree would help a lot. At the very least, you should consider getting a recognized TEFL certificate- a CELTA or Trinity/RSA.

I'm less keen on a degree in English unless you're quite sure you want to spend a long time teaching that subject. Most English degrees in English-speaking countries tend to focus on literature and writing, not on teaching English or exploring the frontiers of using it correctly, and these may be of more limited use in teaching applied English language skills.

If teaching is only a short-term plan, then pretty much any accredited 4-year degree will be fine. Get whatever degree has interest for you and offers you some attractive employment opportunities. In many countries, a Bachelor's degree is the only firm qualification required to work as an English teacher. Bear in mind that many of our home countries (not sure where you're from) are chronically short on teachers, and many places offer the means to easily come back later and get a provisional teaching certificate. This can be upgraded to a permanent certificate if you take a couple of classes. Check your state/provincial Education Department for more details.

For short-term (less than 5 years) teachers with a 4-year degree, I personally feel that a TEFL/TESOL/etc. certificate is a waste of time and money. The CELTA and RSA are expensive and would be overkill; most other certs have little real value or utility. Again, in many countries a 4-year degree is enough. Such a certificate might open a few more doors for you, but you should still be able to find plenty of employers that don't care about it.

The one exception is if you genuinely feel you'd be totally at a loss in front of a classroom. In such a case, a good TEFL cert program will give you some actual experience and pointers conducting a class that will help you be more confident later. However, you can only get these benefits from a real-time, live, hands-on classroom-based course- IMHO online and other such certs are a near-total waste of time and money. Look around- a lot of universities, community colleges, etc. offer such real-time courses; quality is often good and prices are relatively low. It's my opinion that most private TEFL-cert schools are dens of horrendously-overpriced weasels, and you'd be better off avoiding them completely.

Good luck!