There is a #jetty IRC chatroom on irc.codehaus.org
Jetty Wiki
A constantly updated documentation site for Jetty.
Jetty 5.1 Tutorial
A tutorial on configuring and using Jetty 5.1.
Jetty Frequently Asked Questions
User contributed FAQ.
READMEs
CVS HEAD version of the main Jetty readme and also the readme for using start.jar to run Jetty:
Java Doc
The javadoc documentation is the class references extracted from the source code.
This is the primary resource for programing against the Jetty API.
Jetty Mailing Lists
Forums for discussing jetty development and usage.
Source Forge
The sourceforge site hosts the Jetty CVS repository and main FTP archive.
It also provides task and bug tracking tools.
Optimization Guide
Guide for the optimization of Jetty and JVM configuration.
Servlet 2.4 Review
Review of the 2.4 Servlet Specification.
Presentations
Papers and presentations about Jetty and servlets.