A Map is one of the two most essential pieces of navigation gear that you should carry, the other being a compass. GPS may break or fall into disrepair during a PAW, the sun isn't always shining, and it takes a great deal of time and effort to learn to stellar navigation, but a map and compass will continue to work until your break or lose them.
Types of Map
There are many different kinds of map to use, they can be simple, detailed, geologically oriented, and so on. The type of map you choose will have a significant effect on how you navigate, so choose carefully.