Patterns - Start from here

[1] Design Patterns Library - Start here
http://hillside.net/patterns/

[2] GoF patterns - 23 patterns are outlined
http://www.dofactory.com/Patterns/Patterns.aspx

[3]GoF patterns - Listings with UML notations
http://www.tml.tkk.fi/~pnr/GoF-models/html/

[4]GoF patterns - Listings with UML notations and some Java samples
http://www.apwebco.com/gofpatterns/index.html

[5] GOF at Wikipedia - All patterns are linked from here
http://en.wikipedia.org/wiki/Gang_of_Four_%28software%29

[6] Patterns and Software: Essential Concepts and Terminology
http://www.cmcrossroads.com/bradapp/docs/patterns-intro.html

[7] Yahoo! Developer Network - Design Pattern Library
Primarily UI patterns as used within yahoo pages
http://developer.yahoo.com/ypatterns/

[8] Designing Interfaces by Jennifer Tidwell.
Focus on the User Interface Patterns
http://designinginterfaces.com/

[9] Web UI Patterns - A UC Berkeley resource for building web user interfaces
http://harbinger.sims.berkeley.edu/ui_designpatterns/webpatterns2/webpatterns/pattern.php?id=7