I live in East Tennessee, in the small town of Maryville. We are right next to Townsend, at the foot of the Great Smoky Mtns. One really neat thing that happens here every summer, usually early to mid June, is the synchronous fireflies at Elkmont campground. It is the only place in the US that you can see this species of firefly. During their mating season, they light up synchronously. If you are not staying in the Elkmont campground, you can take a shuttle either from Gatlinburg or Townsend to see this phenomenon. My family went for the first time last year. It was really neat! Plus, it's just a relaxing experience.
Cades Cove is another popular attraction in our area. It's an 11 mile loop with pastures, old churches, a mill, and great views of the mountains. It gets very congested during peak vacation times. Two unique ways to see it that I'd recommend are biking or by hayride. Two days a week (I think Saturdays and Thursdays), cars are not allowed on the loop until 10am. Before that, it's bicyclists and runners only. There's a company right by the Cove that operates hayrides in the evenings during the summer and fall. Right before sunset is a great time to see wildlife (deer, turkeys, coyotes, and the occassional bear) with a beautiful view of the surrounding mountains.
Pigeon Forge is full of tourist attractions that are anything but natural beauty! There's miniature golf, Ripley's Believe It or Not, the Dixie Stampede dinner show (pretty good!), Wonder Works, the Titanic Museum, Dollywood, Dolly's Splash Country, and great outlet shopping. Gatlinburg has the Ripley's Aquarium, which is a very nice aquarium! Off of the beaten path in Gatlinburg is the artist community, where several artists have shops.
If you're into baseball, the Tennessee Smokies stadium is at Exit 407 off of I-40. They have a good firework show most Fridays in the summer.
Oh, yeah! If you're here for the 4th of July, Gatlinburg has a huge parade at midnight the morning of July 4th.
Hope this helps you get started!