I'm originally from the Asheville area (actually a bit east of Swannanoa in a little community called Montreat) and still go there several times a year. A couple of venues to check out are Jack of the Wood on Patton Avenue in Asheville and another place called The Grey Eagle. The latter moved a while back and I haven't chased them down since, but they used to get pretty good acts in. You can check them out at http://www.thegreyeagle.com/
There are loads of publications geared to tourism, but one of the best is a tabloid-sized paper call (if I remember correctly) Mountain Xpress. It had the most complete listing and best descriptions of musical acts. It also lists gangs of open mics, but be warned — if it ain't bluegrass or old-timey mountain music it ain't gonna fly. The bluegrass nazis will actually push people out of their circle and close up so "outsiders" can't even see what's going on.
If you like instruments and just looking at beautiful craftsmanship, drive out to Black Mountain (about 15 miles east of Asheville) and go to Song of the Wood on State Street. Jerry Read Smith is the owner and he makes lap dulcimers, hammer dulcimers, psaltries and other instruments that are worth a trip just to see.
If you haven't been to the area before, enjoy the scenery and, if you have time, take a drive up the Blue Ridge Parkway. The views are worth it.