By far the best book I've found on tactics is:
Palatnik, Sam, and Lev Alburt. 2013. Chess Tactics for the Tournament Player. New York, NY: Chess Information & Research Center.
It lists all the tactical ideas, explains how they are mixed, when to look for them, which signs suggest they are present, and more. There is a newer edition out. I still have some minor complaints about the book, but it's still the best I've seen.
Forcning Moves:
Checks
Captures
Threats