Is this the best way for a newbie?! First time was a couple years ago and couldn't ride up a few sections..
A good basic loop that covers most of the park highlights is about 8 miles long, but will feel like much more. Start from the parking lot and head towards the #13 post near the pond. After a few hundred feet, go left at Post #12. Continue across the gas pipeline easement and several boardwalks over the wetlands. The trail comes to a T intersection at Post #10; go left here. The trail is blazed with white squares. Follow the trail until you reach a 4-way intersection at Post #9. Make a right turn here onto a trail blazed with "C". This is a gentle climb up to Post #8. At this point, cross through the chain link fence and pick up the Red blaze trail (round & square). Pass by Post #7 and continue the climb up to Roaring Rocks. Just past Roaring Rocks, the square red trail goes towards the left and the round red trail continues straight. Take the left onto the square red trail - You are now on '3 Amigos'. This trail weaves its way through the boulder fields along the upper ridge for about 1.3 miles and eventually ends at the gas pipeline. If you're pressed for time, you can make a right down the pipeline, but I recommend turning around and riding 3 Amigos back to Roaring Rocks. The trail has a very different flow in each direction and has plenty of challenges to keep it from getting boring.
Once you reach the end of 3 Amigos, go left and continue to follow the round red blazes. The trail eventually brings you to another opening in the chain link fence by post #6. Pick up the white blazed trail here and vear towards the left. This section has some incredible rock gardens. Follow until the trail crosses the gas pipeline. Make a right on the pipeline trail and a quick left back onto the singletrack by Post #5. You are still on the white blazed trail and will remain on white all the way back to the lot. When you reach post #4, make a left onto 'Boulderama'. This trail is one of the highlights of the park. Lots of big rollers, rock bridges, and hucking opportunities. After about 1.5 miles, the trail starts to head downhill through some very technical terrain. On a nice weekend day, you will no doubt encounter hikers in this section, so be prepared to yield the trail. Boulderama dumps you out at Post #1. Continue straight on the white trail and you are back in the parking lot.