One of your first stops should be National Park Center Saxon Switzerland. Here, you'll be able to find your bearings and get some great ideas before you start exploring.
You'll soon see why this Bad Schandau tourist information center is a hit with travelers. If you're searching for other things to see here, Saxon Switzerland National Park, Koenigstein Fortress, and Bastei are in this area as well. They won't take you very long to get to from National Park Center Saxon Switzerland.