How / Should I insulate my Basement Walls
Since you live in Virginia and it doesn't get very cold for extended periods of time and you said that the basement is fully below grade, insulating the basement may not be cost effective.  The outside ground temperature from about 36" down stays approximately 55 degrees the year round. If you have a forced air furnace, you could install a couple heat supplies and returns.  Depending on your end result of finishing your basement the supply registers could be located in the bottom of the supply duct work and the returns should be mounted near the floor level possibly in the furnace return ducting or elsewhere depending upon the basement layout. The supply registers would be open during the winter and closed in the summer. The returns would always be open. This would add some heat to the basement in the winter and assist with the cooling in the summer and keep the basement ventilated year round for comfort. I would probably just use styrofoam mounted tight against the walls and finished as you like. The styrofoam would be it's own vapor barrier. I would however ask builders in your area for their recommendations, first.