You find an agent you want to work with. Tell him/her what you are looking for. They show you some homes, you decide to make an offer. Once an offer is accepted and signed, it is a binding contract.
Basically the same.
As for prices, like anywhere, it's more about what area of a city rather than a city as a whole. Toronto, Vancouver and Calgary are probably the most expensive overall average right now but you can find something to suit your budget in any city. Of course it might not be in the best neighbourhood. Go to mls.ca and you will be able to get prices all over Canada. Do some comparing.