I like the Delorme Atlas and Gazette: one large-scale book for each state. They will show you a fair number of unpaved roads and some trails, and at least give you a general idea of the topography, notable features (rivers, ghost towns, fishing and launch points, etc). They also tie in with the Garmin digital systems, where you can zero in on details.
Speaking of digital, the onX satellite maps can be downloaded to your phone, tablet, and (I'm told) your onboard infotainment system. Except I haven't figured out how to do that. Much more detail. The higher level subscription will tell you who owns land you trek through, very necessary if you're going to hunt, fish, or primitive camp.
There is a new BroncoNation trailmap, but this is just developing data, as members contribute to it. So far, I gather from other posters, not much. Especially in the northeast!
Some people like Gaia GPS online maps, but I can't comment on those. Some spirited discussion on these on the other site. Search "gaia" and "onX" before starting a thread. No harm in resurrecting an old one. High-use off-road areas like Moab, California, and Colorado have 4x4-specific books
As you're new, look into a Bronco regional club, or a general 4x4 group and join them on trips, for the experience and on-trail support if you have a mishap. You can also learn about their modifications and gear. If you're going to hit the seriously remote areas, like eastern Oregon, the Great Basin, Montana, etc. consider Bureau of Land Management maps. Large, very detailed. I'm an old analog type--I love them.
Happy treking!