Call local bike shops to find out more info. The other reviews are accurate. However, I would like to point out that one should stay away after a rain. The area already has a high water table and it only hurts the trails more if you try to ride in the sludge. A pretty good rule of thumb that I have found is if you pull into the grass parking lot and it is wet, go to campus.
Campus is great after a rain being that it is mainly sand and pine straw.
More help is always appreciated in such endeavors. Once on highway 132 proceed for about three and a half miles. Turn left onto Blue Clay Rd. and proceed about half a mile. Then turn right onto Juvenile Detention Center Rd. This road will end at a chain link fence.