I would bring along a book on the local trails or at least a map. There are so many roads, side roads and sub roads that you can get turned around and lost around some of that area pretty fast. It depends on where you're going. Like someone else said too, water and some water!
Enjoy...I'm heading there myself in a couple weeks.
2000 Sahara,33x12.50/15 Bigfoot XT's,Front & Rear Limited Slip Diff's, 9500lb Warn Xi Winch, Air-raid CAI, 4" Susp. Lift, sway bar suspension disconnects, Pro-Comp ES9000 shocks all around, Full roll cage, M.O.R.E. off-road steering box brace, Rear "wilderness" brand rack with tire, fuel cans and jack carrier with bumper, Warn front Bumper/Fender flairs, , Pro-Comp windshield lights, Hard/Soft tops, Smittybilt "C.R.E.S." cargo restraint system, CB, ...blah, blah, blah...