Last year the girls and I entered a bunch of stuff in the fair including our 80 pound giant pumpkin. We're hoping for something over 100 pounds this year. We also entered some sunflowers, and other items from the garden. It was a great shared experience for me, Noel and Lily and they even got $25 out of the deal.
The Deadline for getting in your entry form in is August 5 and you turn them in at the Fair office right by the main entrance to the fairgrounds. Just enter everything that you think you might conceivably have to offer in early September and you can sort it out when you arrive with your items. The entry form is here.
Go here for the full list. Good luck