GPS Information

Hardware

I use Panasonic Toughbooks with embedded, internal GPS units. I use mostly OziExplorer with USGS maps. You really should use OziExplorer if you're using a laptop with a GPS. I have a handheld garmin I keep in my bug out bag along with (2) compasses.

Maps

Thus far the best source to get USGS topological maps (for free) is http://libremap.org/data/ — Even if you do not use them electronically you can print them out and use them on paper.