For recreational navigation planning, we use Benchmark Maps in the western USA. The maps are set up with topo and recreation sections that show public lands, campgrounds, back country roads, and many points of interest that most locals don't seem to know about too.
If a map shows a road, we've found as long as it is dry, we don't have problems with our small class C and toad. The problem is you need a different book for each state. We've got the full set. If comparing to DeLorme's Atlas and Gazetteer, we find the DeLorme product more difficult to read but it seems to have greater detail. The unfortunate part of the DeLorme product is we find many roads that are there, but are not suitable for RV use.
If you want an online topo map to play with, drop on over to gaiagps.com and play with their online map. We use the app for back country exploring with an Ipad in our Jeep. Not a free app, but does everything we need for our desert explorations here in Nevada.