If you can find someone with Arcview8 or 9 and download a geo.tif of the location you want, it is pretty easy to create a shape file and polygons of the subject area. The geo.tif will allow you to easily pick out landmarks and from there you can pin and label them... all from your desk top. A trip with your gps will soon ground truth your desktop work. And as others have suggested, use your gps to create track logs which you can then upload as layers to the main file.
I do this for a living, so perhaps I've over simplified it... Basically the equipment and software has advanced dramatically in the last 3-5 years to a point where you don't need a GIS degree anymore
