Here are some great Backgammon links:

http://www.chicagopoint.com

http://www.flintbg.com/boutique.html

http://www.nvbg.com/

http://home.roadrunner.com/~pgibsonmfic

http://www.backgammonquizcards.com/  (This web site has some great learning tools that will help improve your game.)

http://www.gnubg.org/ GNU Backgammon is a world class backgammon application, and it works on many operating systems. It can play, analyze and teach backgammon.

Tournament and Match information can be found at:

http://www.chicagopoint.com/calendar.html

This is a great web site with a ton of information.  They keep a list of tournaments and matches for the United States and have a section on International tournaments.