This rather lenghty thingy should lead you there...
http://usmilitary.about.com/gi/dynamic/o...26%2Findex.html

If that doesn't work, just do a goodle search for fm 3-25.26, that will lead you to it.

Personally, unless they have changed the manual since the 60's, I don't consider it worth much in the civilian world. If you don't have a GI lensatic compass, with mils and all that, it isn't worth much. Your good old Boy Scout Handbook ('specially one from the 60's or 70's) is better...