We have stayed at the Moab Valley RV park, nice park but you will have to trailer to trails unless you are street legal in Ut. We are staying there in late May 2011.
Went to a jamboree in Moab this April & stayed at the OK RV park, very friendly to ATV & UTV people. Will be going back next year & will stay there again. You can drive in Moab if you are street legal. Just not on the state hyway that runs thru town. You can cross it but not run on it. Great trails ENJOY!
Canyonlands RV park. Nice place good rates. There is a gas station and store at the entrance. It is a one stop shop so to speak.
Unless You are "acting" the fool you should have no problem driving through town to the trails. The locals seem to do there best to protect their main souce of income.