In order to study in Canada for longer than 6 months you need a study visa. It allows you to study on selected universities. You can find out more information about obtaining a permit here:
If year of study is longer than 8 months and you have a permit, you can work off campus for no more than 20 hours per week. Details can be found here:
After graduation, one can apply for a work permit which length depends on the period of study and can range from 1 to 3 years.