For your perusing pleasure:

http://www.fairfaxcounty.gov/parks/bikes2a.htm

http://www.fairfaxcounty.gov/fcdot/bike/

and:
"

The map is available in both print and electronic versions. You can obtain a free copy of the print version at a variety of locations around the County including local bike shops, the information desk at the Fairfax County Government Center, Maps & Publications Center in the Fairfax County Government Center, any district supervisor's office, and the Fairfax County Department of Transportation office in the Herrity Building. For any of these locations we recommend calling ahead to check to see if they have printed versions in stock. We have printed about 6,000 copies in our initial print job and will follow up with another run of approximately 41,000 more in the following months. "

http://www.fairfaxcounty.gov/fcdot/bike/bikemap.htm