For those who want to improve their play (for beginners and more advanced players).
From the knight fork to the Arabian mate and the "Greek Gift":
Ward Farnworth's "Predator at the Chess Board", a Field Guide to Chess Tactics.
http://www.chesstactics.org/
http://www.bu.edu/dbin/law/chess/toc/toc_right_expanded.php
Highly recommended !