Well, on the subject of Quebec City, Ste-Anne-de-Beaupre & Montmorency Falls is a very pretty drive down the St. Lawrence river as I remember it. St. Anne is a catholic shrine, dedicated to Mary's mother--thousands of people claim to be healed there.

On the other hand, the trip to Ile d'Orleans looks interesting too, although I have never been there.

Old Quebec is one of the oldest cities in N.A. and one of the most "european" in flavour. Great for just wandering, although watch out for tourist traps--it attracts millions of tourists every year, and there are lots of restauranteurs out to get your money!

Acadia National Park, by the way, is awesome. Lucky you!