If you are on a regular student visa, you are not allowed to work for the first 6 months except on your campus, that is stocking books in the library or something like that. After 6 months of studying with good academic standing, you may apply for an off campus work permit. According to http://www.cic.gc.ca/english/information/times/temp.asp it takes 20 days to get it if you apply online. It will allow you to work for up to 20 hours a week during the semester and full time during holidays.
You can read about co-op programs here: http://www.cic.gc.ca/english/study/work-coop.asp but you would have to ask the universities you are interested in if they offer that.
You can read about co-op programs here: http://www.cic.gc.ca/english/study/work-coop.asp but you would have to ask the universities you are interested in if they offer that.