Bobco's got the right book.

There may be other good ones too, but John Trout has lots of personal experience with having tracked over 450 shot deer, and has kept meticulous records of every kind of evidencethat can tell a hunter where his deer was hit, whatwounds produce what kind of blood trail.
It also compares and contrasts bullet wounds to arrow wounds.

Lots of good stuff on tracking, and other things too.
Barnes and Noble ordered it for me last year and I had it 3 days.
There is an older book by John too, but I've been told it's out of print.

That book was the best $15 I've ever spent on anything related to hunting, by a long shot.