Just successfully applied VISA to Canada. It's so much easier to get it if you are holding F1 visa in USA. Basically you just need the following documents to be not refused entry to Canada:
2. Application fee
--- paid with money order is convenient if you're not in the vicinity of any embassies
3. I-20
4. Valid Passport
5. Certificate of registration
--- this can be issued at university admission and registration office
More details are posted on Embassy of Canada.