These videos should be watched a couple of times before you attend any land navigation training to ensure you have a grasp on plotting coordinates!
As stated in an earlier post, UTM is the most efficient system you can use to transpose a location from the earth, onto a map. Then you can pass that information on to friendly forces anywhere. Think about the possibilities.
This three video set is without a doubt the best explanation of UTM that I have ever seen. (Hat Tip to Lost Dog). No wonder, it was done by a former member of my alma mater, the 7th Special Forces Group. If you have the time and want to really understand UTM, pop a cold one, turn off the football game, and spend a few minutes learning something of value. He has a few other videos that you might find interesting.