Know the bands before you get to the festival--listen to the CDs, etc. That way you know who you want to see and who you have absolutely no interest in and who is in the grey area where you will check them out and then decide if you are going to stay for the set or not. Even bands I don't care for based on CDs, etc., I will give a chance to in case they are better live than they are on disc. If they continue to not be for me, I hit the vendor room, etc.
The one thing I recommend is to stay near the venue--the Artmore, The Residence Inn. I have done it for 11 years. I find it priceless that I can walk to my room in 5 minutes to grab a snack, go to the bathroom (the venue mens bathrooms can get pretty rank and they are crowded during the breaks between bands). Also, the hotels near the venue are pretty much sold out with PPUSA attendees, which means that there are ALWAYS other attendees all over them. You go down to breakfast in the morning and the place is packed with fellow PPUSA fans. There is always lively conversation, etc. If you want to meet and hang out with people, the near-venue hotels are the best way to do it. To me, its worth the extra money.
Finally, take to heart what everyone else has posted about the PPUSA community--they are a make-shift family of misfits who accept their own. You can go up to pretty much anyone with pretty much any question, comment, etc., and--so long as you aren't rude, etc.--they will accept you, talk with you, invite you for a drink, sit with you, etc. Don't be bashful. Most people there know everything there is to know about some band(s), some genre(s) of metal, some this, some that. We are just dying to discuss our passion(s) with peope who share them and/or want to know about them. We love to teach about metal as much as we love to learn about metal. Also, metalheads tend to have a pretty good--and pretty off the wall--sense of humor. The crowd is generally between 20 and 60 years old. They are medical people, legal people, IT people, restauant workers, factory workers, teachers, etc.--every facet of life you can imagine. There are a lot of varied experiences in the room that make everything infinitely interesting. The crew is friendly and helpful--though some of them are immeasurably busy during the fest--and if you goto the table where they are selling the PPUSA shirts, etc., you can always get some help finding something or finding out something you want to know.
Be ready to have an amazing amout of fun; make some new friends; and wear yourself out with metal, metal, metal.
