Directions can be found here: http://www.ncr.vt.edu/Arlington/Directions.html
Parking information can be found here: http://www.ncr.vt.edu/Arlington/docs/VTech%20Arlington%20Parking%20Information.pdf
If you're taking the Metro to VTRC-A, get off at the Ballston stop on the orange line. http://www.wmata.com/rail/maps/map.cfm