Generics is a Java feature that was introduced with Java SE 5.0 and, few years after its release, I swear that every Java programmer out there not only heard about it, but used it. There are plenty of both free and commercial resources about Java generics and the best sources I used are:

• The Java Tutorial
• Java Generics and Collections, by Maurice Naftalin and Philip Wadler
• Effective Java (second edition), by Joshua Bloch.

Despite the wealth of information out there, sometimes it seems to me that many developers still don't understand the meaning and the implications of Java generics. That's why I'm trying to summarize the basic information developers need about generics in the simplest possible way.

Java Code Geeks : Java Generics Quick Tutorial

how about that angelikalanger site http://angelikalanger.com/GenericsFAQ/JavaGenericsFAQ.html 

and why is this post any better than just a few google searches...

how about that angelikalanger site http://angelikalanger.com/GenericsFAQ/JavaGenericsFAQ.html 

+1. Way superior.

I recommend Bracha's tutorial. The first half is enough for Enerprise Java developers.

http://java.sun.com/j2se/1.5/pdf/generics-tutorial.pdf