Rancocas State forest is split into three areas separated by the Rancocas Creek. One area is in Mount Laurel, one in Hainesport, and the third (best area imho) in Westampton. The site is not being completely cooperative and even trying to get help from admins has proven ineffective. The problem is the whole park is split among three towns and those three sections are separate of each other with a impassable creek between them. The best trail system in my opinion are those found in Westampton. This site defaults to showing GPS data for Hainesport. Bring up the Westampton GPS data for a decent loop through various colored trails. The pictures show the map for the Westampton trail system as well.
The trail system is comprised of mostly singletrack. You'll find some downed logs to jump or ride over. Plenty of root covered paths. Most of the trails are perfectly clear while others are a little overgrown. The green trail has a Strava segment which is fun to blast through. It can be found by following the singletrack path to the right of the main gate on Powhatan Drive. When the path splits, stay to the right. The paths are easily identifiable by painted markings on the trees. If nature is your thing you'll come across plenty of squirrels, deer, streams, clearings, wild flowers, and views of the creek. I'd definitely rate these trails as beginner to intermediate depending on how fast you want to rip through them.