Don't forget to plan to spend some time in the Smoky mountains National Park. It's one of the few parks left that doesn't have an entrance fee (due to some kind of deed restriction when the park was originally built)
There are tons of trails to walk, interesting historical places such as Cades Cove which was an early settlement area. Walk up to Clingman's Dome which is the highest point in the park, and you'll 'see' why they're called the 'Smoky Mountains'
You might even want to drive all the way across the gap and go to the other side of the mountains, and come back.
Gatlinburg is a fun place to visit, and lots of 'tourist' shopping available there. You might ride the cable car up to Ober Gatlinburg just for the fun of it. Once on top though, there's not a lot to do during the summer months. (It's more for winter skiing).
Pigeon Forge is loaded with tourist stuff from typical 'Carnival' type stuff to Go-Carts, to Dinner Theatres, to small water parks, or Dollywood. If you've never been to one of the Dixie Stampede shows, it's well worth it. We go at least once each trip we make there. We've also been to the Dixie Stampede in Branson MO, and the newer one in Florida, just across from the outlet mall, and only a couple of miles from WDW. The Dixie Stampede Christmas show is outstanding if you're ever near one during the Christmas season.
As others have said, post back with any specific questions.