The best mountain bike periodical without peer or doubt is Dirt Rag.
When you want to get on the trail, and stay on the trail, you need organizations. IMBA, MTBAccess.
For touring in the lovely Shenandoah, look no further than www.mountaintouring.com
In Lynchburg, this is the fine central Virginia club: http://www.lynchburg.net/cvma/events.html
For riding about the Roanoke area, with something for everyone, dial up the Blue Ridge Bicycle Club.
For racing and riding around Charlottesville, check out the Charlottesville Racing Club: http://cvilleracing.org/rides.asp
Thomas and Tim run a neat shop in Harrisonburg: www.shenandoahbicycle.com
In Western NC, check out: http://www.blueridgebicycleclub.org