I just got my first mountain bike and I'm looking to put some miles on it in Moab. I've got plenty of time on road bikes but when it comes to mountain biking I'm a beginner so I'd be looking for trails in Moab that suit this style. I'll be heading out there for a few days so any camping tips or locations would be appreciated as well.
Once you get there, any of the bike shops should be able to help out with trail suggestions. Click on "Campgrounds" under "Where to stay" for some camping suggestions. Sorry I can't give any firsthand suggestions.
The White Rim Trail has always gotten rave reviews, but it's a multi-day trip and you'd likely need support.
Most beginners head to Gemini Bridges (one way, downhill, with one monster climb at the end), but my favorite is Klondike Bluffs trail which involves a little of everything, jeep road, dry creek bed, slickrock, single-track...don't forget to check out the dinosaur tracks imbedded at the end of the slickrock section. You have to leave your bike at the border of Arches National Park, but the hike to the Bluffs is short, but the panoramic view is incredible. Before you leave, try your hand at the practice loop on the famous Slickrock Trail...most people enjoy the practice loop, but the entire trail is often too much for first-timers.