If you are willing to spend approximately $2,000, take an on-site Trinity or CELTA course. In Canada, TESL Canada is the norm and it's also highly recognized throughout the world. You can take this one on-site or online and if you take the course online you also need to complete a 20-hour practicum. Also, if you are taking distance learning or online, an ACTDEC UK Level 2 (or more) plus the practicum is recognized by the British Council (So is TESL Canada). Take a course that is recognized by any of the above organizations and you won't need to take any other course.
Online, you can get good courses for US$250-$400. Make sure that the course you choose covers lesson planning, grammar, and phonology. These are good for entry level jobs (many schools require a minimum of 100-hour certification).
We offer the Trinity CertTESOL and TESL Canada on-site courses in Toronto, Canada www.study-at-coventry.com
and online TESL Canada and ACTDEC UK courses www.ontesol.com