Depending on the area you are looking for, the Bureau of Land Management maps are good sources, I actually think they are better than the Forest Service maps in many regards,...and they are generally cheaper. If you are headed somewhere to hunt, check to see if there is a BLM office in the area. They may well have maps of the entire state you are hunting (at least ours do) and you can look for the exact maps you want for the area. They are 1:100,000 scale, which is not as detailed as the standard USGS topos, but they do show topography, land status, road systems, etc.
In addition, many of the National Forests now have "Motor Vehicle Use" maps that are invaluable in terms of showing you where you can legally go on the forest. And even better,...they are free! You can get them at the Forest Service offices in the area you are hunting.
The MVU maps remove any questions about where you can get to on the forest. They show the legally-designated Forest Service roads and trails. ACCESS is a big (and increasing) problem on our public lands. Too many landowners nowadays will try to bluff their way into making you think you can't go somewhere. The MVU maps (and other land status sources mentioned) will give you firm ground as to where you can legally go hunting.
