If you're going to teach English as a second language here in Ontario, you need to be certified and there are a number of potential pitfalls that are rather easy to get caught in.
The first is the difference between TESL Canada and TESL Ontario. You would think that the national body would have more stringent certification requirements than the provincial body. You'd be wrong. While both organisations require an undergraduate degree, TESL Canada level 1 certification (which is the only national level available for pre-service teachers without a Master's degree in TESOL or applied linguistics) requires only 100 hours of theory and methodology study in a "recognized TESL training program or equivalent" and a supervised practicum of at least 20 hours (10 hours of observation and 10 hours of teaching). Applicants must also show evidence of English language proficiency (roughly TOEFL iBT 80).
In contrast, TESL Ontario requires 250 hours of TESL course work from an institution recognized by TESL Ontario and a supervised practicum of at least 50 hours (30 hours of observation and 20 hours of teaching). Applicants must also show evidence of English language proficiency (roughly TOEFL iBT 103).
In other words, TESL Canada level 1 certification is basically useless in Ontario.
The next problem is programs offered by non-accredited institutions. According to TESL Ontario's own application documents, the only certified institutions are Brock, Carleton, U of T, York, and U Sask; Algonquin, Centennial, Conestoga, George Brown, and Humber colleges; Thames Valley, Toronto, and York Catholic school boards; and among private institutions, the Canadian College of Educators and the Canadian Centre for Language & Cultural Studies. The teach abroad courses offered by, for example, Oxford Seminars do NOT meet TESL Ontario certification standards.
Of course, I teach in the Humber program, which far exceeds TESL Ontario requirements, and consequently produces many of the most sought-after graduates in Ontario. The program is unique in having 500 hours of coursework, and 80 hours of graduated practicum which is entirely arranged by the school (many courses leave it up to students to arrange their own practicum hours, which is becoming more and more difficult in the saturated GTA). Humber is a two-semester daytime program, but come September, it looks like we'll probably be delivering it three days a week. If you or anyone you know is interested, please get in touch.