Nighthiker pretty well summed it up. A book or manual can only show and teach you so much. To learn more about tracking, you need to get first hand experience. A good time to do this is when you are hiking. Find one distinct set of human tracks on a trail and see if you can follow the tracks. This may be challenging when the trail has heavy use and it also depends on the trail itself, meaning is it composed of soil, sand, rock etc. You will also have to factor in the weather. Is it very dry which makes tracking more difficult or has it rained and the ground is softer which may show the tracks more easier.

(Slight hijack, but still relevant)

Just yesterday morning we came across a freshly overturned rock that showed ground disturbance where the rock originally was. I was able to determine that this rock was very recently overturned as the disturbed ground was still damp and did not have any dry edges or imprints. I also noted that the soil on the now exposed underside of the rock had not started to dry at all. Notice the pushed down vegetation? These are all important clues as the temperature at the time (10:30 am) was already in the mid 70's and the exposed rock with the soil on it was facing roughly south east. It should also be noted there were no other people in the area and we did not cause this disturbance as it was off to the side of the path.

Here is a link to the picture I took. Any guesses as to what was under the rock that may of interested some animal?

(end of hijack)