Big Country, Stonewall is a good one. I've been told Burnsville lake is a good crappie lake also. I've not fished the main lake, only the spillway and I can tell you it holds several species of fish. I'm in the northern panhandle and don't get down that way often so maybe some of the guys in that area can help you better on how early to go for crappie but I think early april would be good depending on conditions.
here's a link that may help if you know which countys you will be in.
West Virginia DNR - Public Access Sites, Fishing, Float Trips, Impoundments