I've never camped at Pocono, but from what I hear, don't camp in the infield. It sounds like once you get in, you are stuck there!
Advice for Nascar camping.....plenty of beer or other favorite adult beverage, plenty of sunscreen, outdoor games like washers, cornhole, ladder golf, etc. and the normal camping items like food. When we camp at Richmond we take a water barrel with us so we have additional water supply. They usually have septic trucks that will pump your tanks for a fee.
Make sure everybody has comfortable shoes because you will do a lot of walking. There isn't much worse than women who wear flip-flops then constantly complain about all the walking. If you have never been to a race before, try to borrow a scanner and headsets from a friend or you can rent them at the track. Scanner rental is a bit of a PITA because you will have to fight the crowd to return your rental after the race. Either way, I highly recommend having a scanner to be able to follow the race. The MRN broadcast really helps you understand what is going on better plus you have the option of listening in on your favorite driver!