I spent 2 1/2 weeks bike touring around Cape Breton and from Lunenberg to Halifax (self-supported) a few years back. An absolutely spectacular ride! Cape Breton is gorgeous, the climbs are challenging but the scenery helps!

You can travel it in either direction, but I chose to ride it clockwise (the more popular way to go). The winds can be brutal; in fact, I was actually wind bound one day in Chetticamp.
If you get a chance, check out a ceiligh in Baddeck, or any other town along the route.

People are extremely friendly and if I had a dollar for every person who said to me "you're going to ride up those hills?? By yourself?? On a bike??".....

Have fun. It is a beautiful part of Canada.