Several years ago we did a road trip from Orlando to Atlanta, Atlanta to Anna Marie Island on the West Coast of Florida. We had a ball but here are a few tit bits. Never ever over pack your vehicle. It makes for a very unconformable ride during a 9 hour plus car ride. It is easier to pack enough for a week and then do laundry. I know who wants to do laundry on vacation. However, trust me you will appreciate it when your legs are bent like pretzels because you have a suitcase under you feet.
Use the City Pass in Atlanta for attractions. You will find it in the big cities and it saves you money and time for all the major attractions. You will want to book your hotels early and stay near the attractions and the subway. It may cost you a little more in terms of money but you save in terms of time and stress. The trip took a little over a week and was well worth it. I would recommend Atlanta/ Anna Maria Island as a good one week trip.