Well just play around until you find something comfortable. Most people find something close to 12(front)/-9(back) to feel good starting out, but it is just a starting place. Most boards now a days come reference arrows where the binding inserts are which is a good starting width for most.
Also noticed that you are a VA brah...ever been to camelback? If so what is the easiest trail there?
EDIT: Just saw that you actually posted in my camelback thread lol