Over the years I've found a few products that I use over and over again as I work with maps, GPS receivers and geographic coordinates. When ever possible I have arrange to make them available to you as well. I think you will find them just as useful as I do.
Frequently maps come with coordinate marking on the edges, but no grid on the map. This 24 inch cork backed stainless steel ruler, and the archivial quality technical pen are ideal for drawing grid lines. I've packaged them along with a small instruction booklet on gridding maps.

MapGrid Kit

Only a few GPS receivers come with a built in compass. As such they can tell you the direction you are moving, but can't tell you what direction you are facing when your standing still. As such I recommend the every GPS user also carry a compass.

My every day compass is the Brunton 54LU sighting base plate compass. It gives you all the normal functions of a base plate compass. But hold it up to your eye and you can sight through it and get bearing accurate to one degree with great ease.