jQuery is a JavaScript library. JavaScript Libraries simplify how you traverse HTML documents, handle events, perform animations and add Ajax interactions to your web pages. They deliver your code so that it works across all common browsers. jQuery is designed to change the way that you write JavaScript and allow you to add functionality to your pages quicker.
The official jQuery site
Learn about the jQuery JavaScript library, how to install it and how to add functionality to your pages.
http://www.jquery.com
Visual jQuery by Remy Sharp
A quick visual reference guide with examples of what can be achieved with jQuery.
http://www.remysharp.com/visual-jquery
jQuery API by Remy Sharp
Another reference guide to functions available to you in jQuery by Remy Sharp.
http://www.remysharp.com/jquery-api
jQuery General Discussion Forum
This is the best place to post if you have general questions or concerns. Also, if you’ve built a site that uses jQuery, or would like to announce a new plugin, this is the place to do it.
http://www.nabble.com/jQuery-General-Discussion-f15494.html
Learning jQuery
Getting to know the library of choice for unobtrusive JavaScript a an informative jQuery blog.
http://www.learningjquery.com
jQuery Menu Firefox Extension
Add this handy menu right into the top of your Firefox menu and save valuable seconds!
http://www.kintek.com.au/jquery-menu-firefox-extension.html
jQuery for designers
What it says on the tin, jQuery for Designers. A informative blog.
http://www.jqueryfordesigners.com