Tom Brown, Jr., "Field Guide: Nature Observation and Tracking," 1983, about 250 pages. About one-third on awareness and observation technique, including stalking and camouflage; and two-thirds on tracking technique, including pressure releases. Laced with Mr. Brown's beliefs on spirit-in-nature. Filtering out the belief system I found a great deal of useful and interesting information.
I will do a separate commentary on this book along with the three other Tom Brown, Jr. books I read a bit later.
The best beginning book around. The observation skills are more critical to learning tracking than most people are aware of. Identifying the tracks is easy, noticing them and knowing where to look for other sign is much more difficult.