Sites for some other classic games

Renju		Renju International Federation
Shogi		rules British Shogi Federation Shogi.Net home page Shogi variants
Othello, Reversi		rules FDI's Othello links
Xiang Qi (Chinese Chess)		rules World Xiang Qi Federation
Chess and Chess variants		English Chess Federation Chess Scotland Welsh Chess Union The Chess Variant Pages
Draughts, Checkers		English Draughts Association
Kalah, Mancala, Omweso, Wari, etc.		Mancala The International Omweso Society The Oware Society
Amazons		The Game of the Amazons by Walter Zamkauskas
Hnefatafl		Hnefatafl the strategic board game of the Vikings
Scrabble		Association of British Scrabble Players
Diplomacy		The Diplomatic Pouch
Backgammon		Backgammon links
Mah Jong		Sloperama's Mah-Jongg Zone British Official Rules
Card games		Rules of card games Bridge links The Rules of "Pits" (not a classic, but played at some British Go events)
Tiddlywinks		The English Tiddlywinks Association

Mind Sports		Mind Sports web site with information about many of these games
Board Games Studies		An academic journal for historical and systematic research on board games.
Board Game Geek		An list of games and user ratings for them.

A few simple rules ... limitless possibilities