Have a lot of friends who don't speak English and would like to be able to help them in a more effective way. Would appreciate some tips on how to evaluate courses and some idea of how long it takes/how much it costs to get a TEFL certificate
The question is about TEFL, NOT Toefl. I don't need to prove my English, I am English!

TOEFL or Test of English as a Foreign Language is a test which is mandatory for any student who wants to study in a foreign university. You need to clear TOEFL along with a couple of more exams like GRE or show your GATE score ( in case u are an engineering student). Also, TOELF tests your ability to comprehend English as a language and be able to understand the meanings of toughest of English words. The best way to begin is to improve upon your vocalbulary by reading a lot. You can also add those words in spoken english to inculcate the habit of speaking them. You can get a million books and online guidance on how to begin and master English before appearing for TOEFL. FYI, for students who do not know English, it would be a tough thing, but if you are reasonably good at the language then its an easy task to clear TOEFL.

By all means go with the Celta course, it is supposed to be very good. If you get a chance to observe an experienced EFL teacher at work in the classroom, you should take it. Also, to help get across to your friends what you're trying to say, start drawing ... a picture saves you a lot of explaining.

I did the International House course many years ago. They are reputed to be the best, although probably the most expensive. If you want to do this full time the course takes four or six weeks (I can't remember which): I think we were given the results at the end of the course and the certificate follows shortly afterwards. I guess that course would cost over £1000 nowadays: I think it cost £600 at the time I did it: you would certainly be able to find cheaper options.

I think the best way to evaluate courses would be to take a spreadsheet and do an Internet search. Comparing prices and any other factors that you consider important. Bear in mind that you're going to learn as much from practical teaching as you do from the course. A great plus from our course is that there was a lot of critical evaluation of our teaching. We were working in a group of five trainees assigned to two groups of 15 students. I will say that I learnt more about teaching from this course than I did from a one-year post-graduate teaching course.

There are at least two other alternatives to TEFL. One is TESL (Teaching English as a Second Language). The other, particularly if you can speak another language and/or have university certificates (for any degree), is to put on a backpack, call personally at language schools and find a job in another country. I did this in Poland and taught English for a year. There are a couple of books that will help you with this: one is "Work Your Way Round the World".

I think what you should do now is start an Internet search to evaluate the information I've given you. Two colleges that do TEFL courses are International House and St Giles, their websites should give the price of courses. If you have a local technical college start enquiring there, and look at "Footlights", a magazine that lists all evening classes, if you are in London.

I hope that's given you some information to evaluate.

Yes, I did the Cambridge/RSA course at ITTC in Bournemouth 13 years ago.

The course is now called CELTA , see this site for details:

http://www.cambridgeesol.org/teaching/celta.htm

The course I did was enjoyable, stimulating and demanding. It usually lasts 4 weeks but can be done on a part-time basis over a longer period of time. The 4 week course usually costs +/- £1,000.

More information can also be obtained from The British Council which is one of many organisations that administers courses:

http://www.britishcouncil.org/

There are other courses available, the best alternative to CELTA is the Trinity cert. You can also do a course over a weekend or a week at some places but these courses are not widely recognised and provide little or no teaching practice, similarly there are on-line courses available but you'd need to supplement with teaching practice somehow.

Paul suggested the backpackers' route to EFL teaching, this is not recommended as you would a) probably be working illegally if you teach without the relevant qualification, and b) probably acquire bad habits.

Good luck with your plans. If you go ahead with both the course and the teaching, I'm sure you'll enjoy it.

The TOEFL is not a certificate. it's a score you get after being evaluated. The price is around US$150 depending on your location and once you get your scores i think they are good only for one year.
http://www.ets.org/portal/site/ets/menuitem.fab2360b1645a1de9b3a0779f1751509/?vgnextoid=69c0197a484f4010VgnVCM10000022f95190RCRD