Lots of great info on 'first-timing' is available with a quick forum search. EVERY visitor to AirVenture IMHO comes away knowing that one NEEDS a good big-brimmed hat, sunscreen, lightweight rain gear and fantastic walking/hiking footwear (because the venue is at least twice a big as you now think it's going to be) Side note... buses and trams are your friends.

I have grown fond of Frogg Toggs UIltralight rain suits. Low cost, very low weight, the fabric breathes and they work well to keep you dry...… cuz it most likely IS gonna rain/down pour at least once and the raingear needs to be with you.