Go east to Saguaro Park East. After going through the pay both you will be on a one way Paved road. Follow that around to the Cactous trail . This is where you will have the most fun. One thing to be aware of at the beginning near the pay both is a hard right turn down hill.
Many advanced users have crash hard here in less then a few minutes ride.
But take care the trail has plenty of tight squeezes, through some Cactus lining the trail. Overall great for the exercise and scenery. This is a great ride for the beginner and intermediate riders. Bring lots of water if riding in the summer. As others have said this is not an overly challenging trail.