Alistair MacLeod: No Great Mischief.
Call of the Wild and White Fang by Jack London.
Anything by Farley Mowat (Lost in the Barrens is a particular favourite of mine).
Fall on your Knees by Anne Marie MacDonald
Personally can't stand anything by Lynn Cody, I went to school with her and she's a pretentious twit.
John Irving's "Until I Find You" is partially set in Halifax and Toronto (I actually got my first tattoo from one of the characters mentioned in the book).
Douglas Coupland: Girlfriend in a Coma, City of Glass, Souvenir of Canada.
Tomson Highway: Kiss of the Fur Queen.
Donna Morrissey: Kit's Law
I can't remember if any of William Gibson's books are set in Canada...but he's a great Canadian author..
Ami McKay: The Birth House
Wayne Johston: the Colony of Unrequited Dreams.
Jeez, and so so so many more. LOL. I'm trying to think back to all the ones I read growing up!
Oh! and:
Hugh MacLennan: Barometer Rising (About the Halifax Explosion) and Each Man's Son!!!