Tips are expected by service staff, but generally not mandatory. Some accommodation properties will add a service charge if you purchase accommodation with meals. For most situations, anything between 10% (ok, but not great service) and 20% (exceptional service) is appropriate. about 10 years ago
Tipping culture varies a bit province by province. In Quebec, for example, waiters make less than minimum wage because it's assumed they will get tips. 15% there is standard. Since the sales tax you pay in Quebec is roughly 15%, just add the same amount as the tax on your bill.
You'll be expected to tip even for the littlest things, like a bartender handing you a beer bottle. If you don't tip you might get a guilt trip, but use your own discretion. almost 11 years ago