I currently use the following for reading (and transferring) GPS coordinates to a map:

http://www.maptools.com/products/UTMGrids.html

A compass with this built in would be a bonus.

That MapTools website ( http://www.maptools.com ) is pretty nice. They have a good basic tutorial on UTM. They also sell some nice tools like the grid overlay above. Many of these tools are downloadable as PDF's if you want to print your own (on transparency film). The ones they sell are much heavier duty than ones you could make yourself printing the PDF's.