You should be aware that April 15 is a very early time to take the Skyline Drive-Blue Ridge Parkway portion of the trip. It will be perfect for the Charleston-Gulf Coast-Texas leg.

Few of the leaves will be out at higher elevations, and it is possible to have snow. I have encountered it at Peaks Of Otter in Virginia on May 1. This doesn't mean you shouldn't drive parts of it, but it may well be a bit bleak. On the other hand, this is when sex mad animals awaken from their slumbers and seek a heap o' fun, so your chances of seeing wild life are good.

The other downside of these parkways is the very low speed limits, perfect for seeing views and nature but not for making time. You are likely in practice to bounce back and forth between the parkway and parallel highways, Interstate 81, US 11 and US 29, all of which have merits of their own.

I can't quite make out from your post whether or not you want to hike on the AT itself for any distance.

The parkway and the trail are in relatively close proximity between Roanoke and Wytheville, VA, but you will need to check the AT Conference site for details. It is in this area where I 77, the logical beginning of your route to the coast, takes off to North Carolina from Interstate 81.

Hope your seeing 2 or 3 of the Plantation Homes, just outside of NO, on the River Road.

Go through Charlottesville, Virginia and see Monticello(Thomas Jefferson home)--on your way to Nags Head.

Yes, I was confused about the AT as well. You do know that it is a long hiking trail and the the Blue Ridge HWY is the drive?

At that time of year I'd concentrate on Skyline Drive and getting off at Charlottesville. If the weather and/or roads are bad, get off and head to Charlottesville.
http://www.nps.gov/shen/planyourvisit/upload/whole_park.pdf

You could spend the night there or Richmond. Charlottesville to Nags Head is a 4 hour drive so that's a comfortable drive the second day.

Take a look at this list of B&Bs and see what fits your expectations best. http://www.tripadvisor.com/Hotels-g57592-c2-Charlottesville_Virginia-Hotels.html

Personally, I'd stay in Charlottesville for the night, visit Monticello in the morning and then head on to Nags Head -
http://www.monticello.org/

Staying in Charlottesville will work even if you decide to continue on the Blue Ridge Parkway for a while and then head back up to C'ville for the night.

Starrs' advice is excellent. Monticello is a must see. Charlottesville is a university town with lots of hangouts for eating and drinking. Ditto Harrisonburg if Charlottesville is too far to drive on day 1. But you still need to go to Monticello.

We can be more helpful when you clarify your expectations on the Appalachian Trail

Thanks everyone for your help. Following your advice we are now looking to stay overnight in or around Charlottesville, before heading to Monticello and on to the coast.
Let me clarify a few points: we won't be hiking, just taking the skyline Drive before turning off at some point. I was interested in what you had to say about the weather. I have calculated we will be taking the Skyline Drive on April 24th. Am I right to think we should be prepared for any kind of weather?
A few more questions: would you stay in Charlottesville or just outside?
As we approach the coast we are currently planning to drive the James River Plantation Drive, ending at Yorktown. Any advice on where to stay within that coastal area before we head south?
Any tips for the Skyline Drive? Is it easy?
Can I thank those people who provided links to maps and B&B's - much appreciated.

Skyline Drive is very easy. It (and the rest of the Blue Ridge Parkway) is very well maintained. The speed limit is low - to match the curvy road. If you have any driving aggression, the BRP is not the place to be. Folks on the road are just ambling along...enjoying the slower pace and the views. If you find the slower pace is not for you, just get off at the next opportunity.

The road is very well maintained and any sections with icing or poor driving conditions will be blocked off. April 24th is well into spring so you'll be absolutely fine. I think the caution may be if you were planning to hike the AT. A lot of hikers have been caught by unexpected high altitude snowfalls, but that won't be a problem for you if you are just driving through the park. It will probably be sunny and "shirt sleeve and shorts" weather. Bring a jacket in case it's not warm.

This news story may interest those who want to drive the Skyline Drive in April. http://wtvr.com/2012/04/23/weather-snow-closes-skyline-drive/
The NPS closes down the road when the snow starts sticking.
If it is raining or snowing, the views can be less than 1 mile.

This is probably something you are not at all interested in, but if you know of the old TV show "The Waltons" you may be interested. http://www.waltonmuseum.org/

I love driving around the mountains anywhere I am. Skyline Drive and the BRP are gorgeous drives but sometimes it's fun to get out and see where folks actually live. This would give you a loop (returning to C'ville) but with a destination in mind. If you have no idea what The Waltons is/was, you're probably not at all interested.

http://www.imdb.com/title/tt0068149/

Thanks Starrs for the tip about the Waltons. My girlfriend knows the programme very well and it's now on the itinerary. Does any one have any recommendations for the Yorktown,Jamestown, Williamsburg area. We are definitely staying one night. Would it be worth making it a two night stop to explore the area? I think I need to do some research on the history of the area! Thanks again.