I imagine most mapsofts are like maps today. You can get everything from a map of the enite world, country maps, state maps, city maps, or even smaller areas.
The most useful general maps for a small area in North America are probably based on updated versions of the USGS Topographic maps, which cover between 50 and 60 square miles each at 1:24,000 scale.
Take a look at
TopoZone for instance, to see what level of detail they have. For street maps, take a look at something like Google maps to get an idea what the characters should expect out of thier mapsofts.