Also not Canadian, but I got some decent advice when I was there last, and would pass along - there's a "food district" area that you'll want to visit (I stayed in a hotel on Dalhousie, and had a good irish pub, a genuine French-style bakery, a shawarma shop, a beaver tail stand (pastries, you dirty minded few), and several nice sit-down restaurants within three minutes' walk of the door) if you like food. Check out
the Ottawa Tourist board website for events happening in the window you'll be there. If you've got time, since you'll be right there, head to Parliament Hill; and also, check out the War Museum. Gatineau park should be beautiful in the fall.
I drove in to Ottawa about three hours after they won the hockey gold medal in the Olympics. That was some impressive impromptu parading.
blotunga: I might not even need a car if buses and trains are reliable and abundant.
Public transport was very good to my expectations of US standards, but it wasn't quite as good as you'd get in the downtown areas of most major European cities. If you've never been to Niagara Falls, it's worth a trip. Try to get signed up for one of those little boat trips where you put on the raincoat and they take you right up to the base of the falls. Such power ^_^
skeletonbow: Best New Orleans food in the universe (assuming they're still there).
...better than in actual New Orleans? ;)