I and a couple friends did this ride a couple years back. The biggest suggestion I'll add is to make sure you have enough time. There's a lot to do and see in that loop, and you don't want to rush it if you have a choice.
We actually rode it in about 3.5 days, and didn't have nearly enough time to wander like we should have.
The nice thing about Ontario is that the Province puts up signs for everything, so you'll not have too much problem finding what you're looking for..
Oh, and look out for moose. There's a sign warning you of this about every 3-4Km, so by the time you get home you'll be looking for moose everywhere.