I was planning on day tripping, leave Saturday morning around 7 am. However, if you dont mind rough camping GWNF is really better for camping than wheeling. If it is clear you can camp on top of a mountian (2-4,000-feet elevation) and the star gazing is spetacular. There are also numerous spots beside mountian creeks, but there may not be much water these days. The best wheeling I seen in the forest is around Rawley Springs, northwest of Harrisonburg. The best camping spots I have seen are southwest of Harrisonburg, around Reddish Knob. When I plan a camping trip to the forest I usually just explore until I find a camping spot I like.
If you have never been to the forest, I would suggest going to a book store and picking up a Gazattere for VA. It shows all of the public roads, elevations and even some of the more traveled trails.
Also If you are to lazy to get out, go to the web sit topozone.com and enter Rawley Springs, VA. You can brouse the USGS topo maps that show even more detail than the Gazateer. Just remember that not all of the trails are open.