Open your USGS topographic map and look for a small diagram next to the scale bar at the bottom of the map. The diagram has a vertical line leading to a small star above it which represents the North Pole. This line represents true north, also known as geographic north, or GN.
Note the angle, or number of degrees, printed next to the second line leading out at an angle to the left or right of the vertical line. The top of the second line will read "MN" or magnetic north, and shifts slightly over the years according to the Earth's magnetic activity. The difference between zero degrees, or geographic north, and the angle for "MN" written on the map, is the angle of declination, and you should have the most current map available for the correct declination.
Align the magnetic north reading with the "N" on your compass, by moving the dial the number of degrees of declination to the right if you are on the left of the vertical, and to the left if you are on the right of the vertical. Doing so aligns you with the magnetic lines of direction pointing north; relying on true north puts you on a course with an angle of error equal to the angle of declination and you will be off target.
Turn in the direction you plan to go. Hold the compass with the needle lined up with the "N" of north. Line up a distant hilltop or a tree ahead of you against the degrees marked on the compass. An angle of 90 degrees from north is due east, and an angle of 270 degrees is west. 180 degrees is due south. The number of degrees away from north represents the azimuth, or angle of direction.
