There's no French people in Canada. Just some crazy seperatists over in Quebec that we put up with.

Seriously though, it's fairly straight forward, if you live in Quebec it's expected that you know French to get most jobs there. If you live outside Quebec, it's expected you know English. Nobody requires you to know both, though the tourism industry does list it as an asset, they will not disregard your application because your uni-lingual.
-m