PMM said:
Hi
1. As a US citizen, you can apply at the border or if flying, the airport. Note you will require proof of funds, for 1st year's tuition, $10K for settlement funds, $2K for travel and letter of acceptance.
The requirements are to have proof of financial support.
http://www.cic.gc.ca/english/study/study-how-documents.asp#doc3
It's tuition plus $10,000 (no travel funds required), and it is acceptable to use other forms of proof (such as a job offer). They have had little abuse from the US, so in my case, stated income and assets was sufficient. I had the documents (always a good idea), but the officer wouldn't even let me show him them (this was in YVR).
Depending on the circumstances, they have the option of accepting letters of financial support from parents, employers (foreign), student loans, etc.
On the other hand, countries that have had more issues with overstays and illegal work will tend to get more scrutiny. If the country has had fake bank statements, they are more likely to verify with the bank.