Dan,
Once you get started I think you'll find it a lot easier than it looks right now.
I learned the old fashioned way, before there was good software to sync your GPS to a topo map. You can buy maps directly from the USGS, and sometimes a physical map is much better than a map loaded in a GPS unit. Your GPS unit will report (coordinates) latitude and longitude (X.xxxN, X.xxxW) which is basically an imaginary grid placed over the earth as reference. The first number is also called "northing" where you are vertically on the map, the second is where you are horizontally. The easiest way (for me) is to read the coordinates off the GPS unit, then find those coordinate on a physical map. Latitude and longitude are printed on the edges of USGS topo maps.
Also, in Google earth there is a "Fly To" box in the upper left. Enter your coordinates from the GPS in there and it will take you to that spot.
There are many coordinate "systems" that can make things confusing, but they are all based on the same principle, and Google Earth is smart enough to tell the difference, so just enter them as they appear on your GPS unit.
Go try things out in the yard and I bet you'll have the hang of it pretty quick.