CPSC 310 Course Notes by Gene Lee
An awesome resource!

Design and Object Factory: Design Patterns
The Design and Object Factory has a great page for learning about the different types of design patterns. Each pattern that's listed here has a detailed overview of the pattern plus code samples showing how to use it.
http://www.dofactory.com/patterns/Patterns.aspx

Design Patterns Tutorial
This design pattern tutorial, created by Brian T. Kurotsuchi, provides a conceptual overview of design patterns plus a few examples.
http://www.csc.calpoly.edu/~dbutler/tutorials/winter96/patterns/

Design Patterns, Pattern Languages, and Frameworks
Douglas C. Schmidt's site on design patterns provides information on both design patterns and frameworks, including links to other patterns and frameworks resources.
http://www.cs.wustl.edu/~schmidt/patterns.html

Hillside.net - Your Patterns Library
A great site for information about design patterns. They've also produced a book on design patterns.
http://hillside.net/patterns/

The Design Patterns Java Companion
This site contains many PDFs with information about design patterns.
http://www.patterndepot.com/put/8/JavaPatterns.htm

Design Patterns - State
This site contains detailed information about the state pattern.
http://ux-2d00.inf.fh-brs.de/home/patterns/korea/state.htm

State
This site contains detailed information about the state pattern.
http://home.earthlink.net/~huston2/dp/state.html

Design Pattern Synopses
This site contains detailed information about design patterns, including information regarding related patterns.
http://www.mindspring.com/~mgrand/pattern_synopses.htm

An Object-Oriented Pattern Digest
This site contains detailed information about design patterns, including information regarding related patterns.
http://patterndigest.com/