Personally, and being a Michigander, we never even stop for gas until we're over the bridge. That said, the above suggestions are good. Be sure and add to the list; Muskalouge State Park and our personal favorite, McClain St Park in the Keewenaw. As for sightseeing, hit the Michigan Welcome Center rest area when you get into MI. Pick up list of waterfalls and lighthouses. When you get to da UP, Whitefish Point, Seney National Wildlife Area, and in the Keewenaw, several copper mines are definites on the list. Straits St Park, just over the bridge is a great "stopover" park and always has spots. Coming back, outside the Soo, is Brimley St Park (complete with casinos if that's your thing). Have fun and enjoy!