http://www.nasaproracing.com/hpde/preparing.html
http://www.nasaproracing.com/hpde/firstday.html
http://www.nasaproracing.com/hpde/passing.html
http://www.nasaproracing.com/hpde/theline.html
http://www.nasaproracing.com/hpde/inslow.html
http://www.nasaproracing.com/hpde/limit.html
http://www.nasaproracing.com/hpde/weighttransfer.html
http://www.nasaproracing.com/hpde/rollover.html
http://www.nasaproracing.com/hpde/heelandtoe.html
All of these pages from NASA are worth reading if you haven't already. Remember your going out there to have fun (I hope) Pay attention to your instructor's advise, he know's what he's talking about. I just finished my first year of HPDE driving, advancing to HPDE 4, and it was a blast !! My accounts of the adventure are found here
A first year of racing
Yes, I was out racing again !
Sounds like you got the basics covered on the car, remember a tire gauge, and an airtank if you've got one. Tire pressures can really affect your handling on a road course. The NASA links above have good suggetions for stuff to bring. Have a ball, let us know how it goes !!