Going on the 'official' off-road trails is fun and we've used the Wells and Massey books but if you want to mix in some easier scenic drives on actual back-country roads, pick up the Benchmark Atlas for Utah. It has very easy-to-read maps along with specifying scenic sites. The Benchmark series is made for all the western states and we use them constantly. They're excellent!
Also, especially for the Moab area, just go into the local Visitor Center and they'll have maps of the more popular trails. Have a good trip!!