Meta:Links

Looking for more puzzles? Try these excellent sources.

Websites

Car Talk Puzzler - sometimes automotive, sometimes more math/logic based.
Maths is Fun - math and logic puzzles appropriate for math education.
Problem of the Month on Math Central.
pzzls - nice site with a good variety of math and logic puzzles, as well as some others.
Richard Wiseman's Blog - new puzzle every Friday, answers on Monday.

Problem Solving by Thomas DeFranco and Charles Vinsonhaler.
Problem Solving Through Recreational Mathematics by Bonnie Averbach and Orin Chein.
Books by Martin Gardner - perhaps the greatest contributer to mathematical puzzles ever.
The Riddle of Scheherazade: And Other Amazing Puzzles by Raymond Smullyan. Very nice collection of puzzles, all tied together in a story. Plus, some logic content as well.
Sideways Arithmetic From Wayside School by Louis Sachar. A collection of cryptarithmetic puzzles.

Mind Trap - a game with hundreds of puzzle cards. Lots of lateral thinking puzzles.
Professor Layton and the Curious Village - for the Nintendo DS. Loads of puzzles wrapped up in a fun mystery.
Professor Layton and the Diabolical Box - sequel to the Curious Village. Another great Nintendo DS puzzle game.