Brenden, you should be able to licensed at any NASA event - you need to have completed the pre-reqs of (I believe) 8 days of HPDE and/or the DC school. From experience, I would say 8 is a BARE minimum and you may be more comfortable with a few more track days than that, especially in HPDE4, because you learn so much about getting comfortable in traffic and passing situations. DC schools is really good, and I would consider it a nice "add" to driving days, not a replacement. In DC you do things like an entire session of side-by-side, another of just rolling starts, testing on flags, etc. No substitute for seat time and any driver would want enough that they are totally comfortable in racing situation. Even if you don’t race, come out to the HPDEs and paddock with us E30s until you are ready - would be great to have you out there.
In order to get set up for licensing, you need to submit your app, check, and medical exam 2 weeks prior to the track date - the instructions are on the nasa site. Look forward to driving with you in 2008.
Cheers,
AJ