We stayed at Battle Run Campground on Summersville Lake off US19. Water and electric on lake with dump station. 20 miles north of New River Gorge.
www.recreation.gov
We liked the Cass Scenic RR although it was foggy the day we went and the views from the top weren't that great. We still enjoyed it.
Another park that gets good reviews for things to do is Canaan Valley Resort State Park. I don't think the campground gets excellent reviews but all the things they offer there keep you busy.
West Virginia is a beautiful state! We also thought Harpers Ferry was interesting but that's too far from where you want to stay.