The GWNF is very large. Where are you located? You won't bang your Jeep up on Peters Mill. You can only go so far on Taskers Gap road. Those ATV trails don't permit autos on them.
Other than that, there's Flagpole, Second Mtn, Dictum Ridge, and Feedstone in the Long Run complex down by Harrisonburg. Further south by Lexington you have Shoe Creek and Big Levels.
Here's another link with some more info.
Northern GWNF Trip Report
Other than that, get the Nat Geo Trails Illustrated maps and download the Forest Service's GWNF MWUM.
If you haven't joined a club I recommend joining one. You got NOVA Jeepers, OCC, and VA Jeepers to name a few.
There's also the commercial parks which are more oriented to wheeling than the GWNF. You got a Big Dogs event going on near Winchester this weekend and there are some club outings up to Rausch Creek taking place over the next few weeks.