Forestville is a fun location to ride if you're looking for more family oriented trails. I thought the fees were a little steep for camping, but that's the way it is in MN. We had the entire campground to ourselves basically because we were there Sunday - Tuesday. I've heard it gets packed on nice weekends though. As far as the camping, it was pretty good, though we had a problem with bees in the tree above our site - they got annoyed with the fires and kept getting into our tent. Also, dumb of us, but we left a small pile of Cheetos on the ground overnight and the raccoons were fighting over them.
As for the trails, they're good. This is not my favorite place to ride, but it is good. I highly recommend shoes because the trails are paved with crushed limestone. If you go out one way on the trails, you'll do a bunch of simple trails in nature. If you go out another way, you'll do more challenging trails with many, many water crossings. Those are fun! Bugs weren't bad this time of year, either.