I use Expertgps software (http://www.expertgps.com) with my Garmin 12 GPS. The newer GPSs have more options, but it works for me. The software downloads the map image over the net and then overlays the tracking on it. You can zoom in for a more detailed map if you wish. It also offers the use of aerial photos, instead of Topo maps. Some new GPSs come with a data cable to hook to your computer and it's own software.
Jack