The main functions of using a compass are:
- to tell which direction you are traveling – your heading
- to tell which direction an object is from you – its bearing
- to keep you following a straight line of travel
- to help orient a map and align it with the actual land
- to perform triangulation and determine your exact location on a map
- to plan routes and determine directions and distances of travel
I found a great site called Compass Dude with information about reading a compass. The site covers
- Compass skills including Reading a Compass and Using a Compass
- Map Skills including How to Read a Map, Understanding Map Scales, Map Symbols and How to Read Topographic Maps
- Using a Map and Compass together including Understanding Latitude and Longitude, Compass Declination, How to Read a Heading, Orienting a Map, Performing Triangulation, Plotting a Route and Pacing
- and finally, Finding Direction with No Compass
