Trip Planning from West Coast to Tennessee

[RejoiceWay]

We have a family reunion near Denver next summer and plan to drive in our TM from Seattle. Unfortunately, the reunion is set for July 5th, so it'll be a busy travel season (we usually wait until before/after school is in session to travel). Since we'll be half way to our friends in Tennessee, I'll be continuing on for a visit (just north of Nashville). While there, plan to make arrangements to take the TM in for a tuneup. We all will then go on to visit a mutual friend in NC (east of Wiston-Salem). Since it will be the middle of summer (hot), and the busy travel season, could you give us recommendation on the campground situation in that the Tennessee area. How far in advance are reservations necessary, what campgrounds are recommended (state parks, or ???), and what "must-see" areas do you recommend for folks like us who enjoy the outdoors? We're open to ideas and because we're planning so far in advance can adjust our schedule accordingly. Also, are there camping books that are recommended (AAA has discontinued their little camping books and they don't even have anything available to purchase - sold out until after the first of the year)?