http://chess.about.com/
http://en.wikipedia.org/wiki/Chess
The following are extracted from Wikipedia:
Chess is played on a square board of eight rows and eight columns of squares.
The colors of the sixty-four squares alternate and are referred to as "light squares" and "dark squares".
The players are referred to as "White" and "Black", and each begins the game with sixteen pieces.
These consist of one king, one queen, two rooks, two bishops, two knights and eight pawns.
Pieces are moved to either an unoccupied square, or one occupied by an opponent's piece, capturing it and removing it from play.
With one exception (en passant), all pieces capture opponent's pieces by moving to the square that the opponent's piece occupies.
When a king is under immediate attack by one or two of the opponent's pieces, it is said to be in check.
The object of the game is to checkmate the opponent; this occurs when the opponent's king is in check, and there is no way to remove it from attack.
End of the game
Chess games do not have to end in checkmate — either player may resign if the situation looks hopeless. If it is a timed game a player may run out of time and lose, even with a much superior position. Games also may end in a draw (tie). A draw can occur in several situations, including draw by agreement, stalemate, threefold repetition of a position, the fifty-move rule, or a draw by impossibility of checkmate (usually because of insufficient material to checkmate).