what are the rules for going past the 50 move edward

Typing "50 moves" into the forum search tool finds, for example, this thread:

http://www.chess.com/forum/view/general/50-move-rule2 

cut n paste, wow...

The fifty-move rule is that if fifty moves go by without a pawn move or a capture or checkmate, then the game is a draw. The rule rarely comes into play. One case where it suddenly becomes important is in the forced mate with a bishop and knight against the bare king; this can take thirty-something moves, and if you slip up you can easily exceed the fifty moves. Even grandmasters have failed on occasion to win with the bishop and knight because of this rule.