I'm just west of Mt Airy about 10 miles and spend a lot of time up around Galax and Fries Va. There is a lot of great riding up in this area, from heeled over street riding to full knobbies only trails. All we need is a warm day. If it's 50 in Winston it's 40 up the mountain in Va. So this time of year forward I'll spend more time riding to the east and west of Mt Airy and stay a bit warmer.
Get yourself a Delorme North Carolina Atlas and Gazeteer and do some exploring. It shows terrain and all of the backroads you can dream of. The routes that others have posted here already are a great starting point.
Safe & fun travels to ya',