As for protocol and whether you should wait till sun-up... I would want to get in as early as possible. Better to start setting up your camp before stuff starts getting hot. Last year we arrived at 4am and started setting up, and we never slept until later that night. I think it adds an immediately fun element to start off sleep deprived (seriously) . Plus, it will be more fun to arrive when all the blinkies have already started.
"just two indecisive cowboys, trying to play a word game." - piehole "Just apply intelligence and discretion and you should be able to get away with just about anything." - Ugly Dougly