If you want to know about the Fair grounds itself, they have a lot going on during the year such as flea markets going on during the weekends. They also have gun and knife shows.
The Flea Market is small and mostly used items outside, and the newer stuff inside. Its a good way to waste some time during a weekend.
The actual fair takes place around Halloween. Each year I get a little more disappointed with the fair. It becomes a breading ground for illegal drugs and strange people.
If you are going to go, I would advise going during the day, and skip the Midnight maddness that they feature each year.
I enjoy going to the different booths and exibits, and viewing the animals. The actual rides I would not allow my children to no longer go on, because many of the workers are high on drugs, and barely sober.