Terrain association is probably the most vital skill of a land navigator. Armed with a good map, and the ability to relate it to the terrain, you can navigate anywhere.
Having done these things, you now need to practice relating what you see on the ground with what you see on the map, and vice versa.
One way to do this is to get a topo map, and get outside and go to it. That's the way a lot of folks learn. But there's also an armchair way, when you can't get outside to practice. I've found Google Earth to be a great learning tool for practicing my terrain association.
Here's an example of what you can do--
Let's say you have a USGS topo map of North Carolina's Shining Rock Quadrangle. The contour interval is 40 feet, and the contour lines depict the shape of the terrain.
What you want to do is go to that spot in the world on Google Earth, and then practice relating what you see on Google Earth with what's on the map. Pick out saddles, hilltops, ridges, and so on. "Follow" creeks, noticing surrounding hilltops.
You can armchair navigate all over the wilderness like this, gaining as you go experience that can help you do the real thing.
Measure azimuths and distances from one place on the map to another. Then, compare with Google Earth, which has a line feature, giving you the azimuth and distance of your line.
Find the UTM coordinates of places, then see what Google Earth says. They won't match up exactly if your map uses a different datum than does Google Earth.
Of course, you can work with any topo map, but you might want to get one a really mountainous area that has a lot of distinctive terrain features.