The pattern home page: http://hillside.net/patterns/ See DesignPatterns for a more in-depth discussion
Random Links
http://www.industriallogic.com/patterns/ The Grand Daddy of all patterns study groups, the Design Patterns Study Group of NYC is now over 2 years old! They meet every Monday evening in Soho and cover design patterns and pattern languages.
http://www.enteract.com/~bradapp/docs/patterns-intro.html Brad Appleton's Page (contains an excellent introduction to patterns)
http://c2.com/cgi/wiki?WelcomeVisitors Wikiwiki web
http://www.agcs.com/patterns/chiliplop/ AGCS - Chili PLoP '98
http://www.radsoft.com/patterns/index.htm Phoenix Patterns Group
http://g.oswego.edu/dl/ca/ca/ca.html Christopher Alexander: An Introduction for Object-Oriented Designers
http://www.bell-labs.com/~cope/Patterns/ICSE96/icse.html Industrial Experience with Design Patterns
http://members.aol.com/mdturner/patternsclass.html OOD using Design Patterns Course (contains power point presentations for the class)
http://www.quintessoft.com/ Quintessoft (contains a C++ s/w that uses design patterns)