Books

Chess and Checkers : the Way to Mastership
by Edward Lasker
http://www.gutenberg.org/etext/4913

Chess Strategy
by Edward Lasker
http://www.gutenberg.org/etext/5614

The Blue Book of Chess
by Howard Staunton and Various
http://www.gutenberg.org/etext/16377

Websites

Chess Guru
http://www.chessguru.net/

FICS Teaching Ladder
http://www.freechess.org/Ladder/index.html

Google Directory
http://www.google.com/Top/Games/Board_Games/Abstract/Battle_Games/Chess/

Openings

ChessOps
http://www.eudesign.com/chessops/

Tactics

Predator at the Board
by Ward Farnsworth
http://www.chesstactics.org/

Software

Jin
http://www.jinchess.com/