You can do alot of the trails in Moab with minimal risk of damage--alot of stuff has by passes that you can opt for if you're not comfortable. One of the best things I did while living there is go to the State Map Supply (not sure of name, but it's close) and buy a book on Moab trails. It'll give you lengths and trail ratings for each.
Of course you can always go to the Outpost (aka Neo's place) in Moab and fall in with a group doing daily runs. Those guys will learn you the ropes without letting you destroy your truck.
One thing you have to go watch the big boys do is Potato Salad hill; it's got to be the shortest obstacle there (just a hill), but it's intimidating as hell and I wouldn't do it in my 3. I saw several 2's have a go, and the 1's are a blast to watch.
As for trails in Salt Lake, I lived in the Layton area and used to go play in the Farmington Canyon area, there's some fun smaller stuff to get into, and some really nice trails to explore all up in the mountain. There was a guy on the forums I haven't seen in a long time, D1RK, that lives in American Fork that knows alot of the local trails as well.
There is a local forum for that area, can't remember the name right now, but alot of guys post up looking for people to run trails with them. I envy you in that area as there is alot of fun stuff to do around there.
Got it, it's called Rocky Mountain Extreme 4x4-----
http://www.rme4x4.com/forum.php?
There are several forum members in the Ogden/Layton area that would probably be up for a run if you post up here.
Good luck!