GPS technology has come a long way. My first hand held GPS had a basic base map with major roads and no expandability. It could tell you where you were and where you had been, but it wasn’t always useful for telling you how to get where you wanted to go unless you could walk in a straight line. Now hand held GPS units have evolved to the point that they have touch screens, incredible accuracy, and the ability to display complex topographic base maps. These base maps make the GPS infinitely more useful but they tend to be relatively expensive unless you know where to look.
I recently came across GPS File Depot (GPSFileDepot.com) which is an online repository for free GPS map data from around the world. They have topographic maps, detailed road maps, trail maps, land usage maps, and several other types of very useful maps. I have downloaded several maps that have all been accurate and easy to use. The amount of useful data that is available on this site is staggering.
Keep in mind that these maps represent a significant amount of work on the part of the creators so if you download you may want to consider donating to the site.
If you want to get the most out of your GPS, check out GPS File Depot.