I got it. There's a $15 entry fee The show starts at 9am so I'd suggest aiming to get there at 8am. Here's a phone number for additional information 401-841-0707. Judging is from 11am to 1pm and the show ends at 2am.
They have a page that is hooked up to google maps for directions. This is it obviously
http://www.fortadams.org/direct.htm
If you want an address to plug into your gps here ya go
North Lawn, Fort Adams State Park, 80 Fort Adams Drive, Newport, RI 02840
If you guys want to get together and get a something to eat afterwards I've found a 99, and Applebees, a Chilis, a few pizzerias, and a restaurant joint called Juicy Cheesy Burger right near the carshow