Tactics book recommendation needed

Mating the Castled King
Invisible chess moves
Encyclopedia of Chess Combinations

Have a look at chesstactics.org, which is the legit free online version of Wade Farnsworth's excellent "Predator At The Chessboard."

The site is pretty basic, but it is a very thorough and clear exploration of tactics.

Remember though: the sorts of positions that come up in tactical puzzles don't arise all that often. He also has to learn how to play the game. :)

#9 You can always punch the positions into an engine (if somebody else hasn't already annotated them in depth). As long as there's a tactical solution, the comp should be able to solve it for you unambiguously.

Winning Chess Tactics by Seirawan

@sumiraghav
auerswald.pgn is a collection of 3500 puzzles with solutions. You need a pgn viewer or GUI to open the file. Most puzzles are from actual chess games.