First off, read up on proper 4 wheeling tips. there are quite a few rules that all "real" wheelers go by.
* Never leave trash on the trail. If you packed it in, you pack it out.
* Water crossings, drive slow and make sure your rig isnt leaking any fluids that will harm the habitat of the wild animals that live there. Everyone likes to spash through a stream and make a lot of white water, but your damaging the banks and the bottom of the stream, drive slow.
* Know your vehicle and its limits, going gung-ho over or through something is asking for trouble and breakage, and dangerous to you and passangers.
* Be ready for things to break, and if you get more serious into it, bring spare parts for most commomly broken items.
* Be courtious to other people wheeling, hiking, fishing, or enjoying the area.
People who dont do these things or act like jackasses are the ones who make off-roaders look bad, and gives groups like the Seirra Club more ammo to close down public trails. Be safe, and have fun, and think with your head.