Equifax and Transunion, as mentioned before, those are the only two options to check any Canadian's score. You need to cough up money for it each time you check your score, as they are For Profit companies.
They take all info from creditors, so it's a pretty fucked up system. Utility bills (telecom, energy), banks, and credit card bills will regularly report to them...and that affects the score. Obviously loans of any kind will also affect score, as will late bill payments.
If you're looking at buying house or anything involving banks or loans, the financial firms will always check those 2 mentioned (Equifax and Transunion). Transunion has a physical office in Oakville, Ontario (and other provinces). The other one doesn't...must mail shit back and forth.
If there is any discrepancy with those two firms, you will be denied everything. I got denied for a free credit card that my unemployed friend got, because there was some issue with equifax or transunion. Still looking into that mess...ugh. Get a score and a history to make sure your (or gf) record is golden.