Awesome that you are camping. Are you guys looking for Waterfalls, Mountain Vista's White Water Rafting? Fishing, History? Are you driving or flying?
If I were flying in and had 3 days, And I wanted to see waterfalls, I would go to Asheville N.C. I would spend my first day at Biltmore Mansion
then head S.W. to Transylvania County,
"The Land of a Hundred Waterfalls". Dupont State Forest , Triple Falls. There are a lot of waterfalls in a very small area.The Waterfalls here are Tall Wide and fast flowing. They are also short moderate hikes, and some are handicapped accessible.This waterfalls was used in the filming of The Last Of The Mohican's movie as well as a few others.
Waterfalls in the Asheville area. http://www.romanticasheville.com/waterfalls.htm
If I had a week, I would Drive to West towards the Great Smokey Mountains. Taking From the intersection of Hwys 64, 280 and 276 north near Brevard, drive north on Hwy 276 for 7.5 miles and turn left into the parking area. This is sliding rock. We always stop for this one, but be warned, these are mountian streams, and are always cold. :) Here is the link.
Continue on 276 to Waynesville, N.C. And go to GSMNP Catahoochee Valley,http://www.nps.gov/grsm/planyourvisit/cataloochee.htm
For a small, low traffic area, great for viewing Bears Elk, and historic home sites. I would plan on Spending the night near Maggie Valley.
Day 3 Drive to Cherokee N.C.
I would consider going to Occonuffalufftee Indian Village while in Cherokee.
From here I would have to decide to A) Drive thru the Great Smokey Mountians towards Gatlinburg, And tourist trapps, Or head west towards water and ;less people.
We perfere less people, so we would head west to Bryson City N.c. and GSMNP Deep Creek where I would camp or reserve a cabin @
We spend 5 days at this campground and tubed everyday. There are 3 nice waterfalls within a mile.
If not spending the night here, I would look for camping @ http://www.nantahala-river.net/
Or drive another 2 hours to the Ocoee River. This is the place to White Water Raft. The best Campgrounds are Government owned. http://www.tn.gov/environment/parks/Hiwassee/
Its always a good idea to sleep after rafting. lol! :)
From here you could head towards Knoxville Tn then stay for some civilized fun,
or head on up to the Tn./ Ky state line to Cumberland Falls. If you are there at night on a full moon, you may see a moon bow!