eh is more common at the end of a sentence than the beginning. It's like the American favourite - 'you know' in some regards.
Wanna play hockey eh?
Don't even think of throwing that snowball at me eh!
And yes, it is very common. Unlike the American injection of 'you know' and 'like' into common speech being an indicator of low i.q. or lack of a proper education, eh is used by Canadians of all educational levels.