I Just finished reading Learning jQuery 1.3 by Jonathan Chaffer and Karl Swedberg.
This book provides a really indepth overview of jQuery along with many real world code samples. Its very well written and talks about all necessary topics from getting you started to Selectors, Events, Effects, DOM Manipulation, AJAX, Table Manipulation, Forms with Function, Shufflers and Rotators, Using Plugins etc.
It also talks about advanced topics like extending jQuery and writing your own plugins and contributing to the jQuery community.
They also talk about the jQuery UI plugin, jQuery UI ThemeRoller, Lightboxes, Modal Dialogs and other popular jQuery plugins.
Would highly recommend this book to anyone who is getting started with jQuery or is an experienced developer looking to get a better understanding of jQuery and the power it brings to the front-end developers.
Here is a link to this book on Amazon.
http://www.amazon.com/Learning-jQuery-1-3-Jonathan-Chaffer/dp/1847196705
Also read their Blog entries here:
http://www.learningjquery.com/