Although we as authors naturally like to think that our book is all you'll ever need to become a JavaScript expert, we recognize that you might want a bit more information after you've eagerly devoured ours. There are approximately a zillion JavaScript books on the market; here are some of the books that we recommend:

Ajax Hacks by Bruce Perry

Ajax in Action by Dave Crane, Eric Pascarello, and Darren James

Ajax Patterns and Best Practices by Christian Gross

Beginning JavaScript with DOM Scripting and Ajax: From Novice to Professional by Christian Heilmann

Beginning XML with DOM and Ajax: From Novice to Professional by Sas Jacobs

Bulletproof Ajax by Jeremy Keith

DHTML Utopia: Modern Web Design Using JavaScript & DOM by Stuart Langridge

DOM Scripting: Web Design with JavaScript and the Document Object Model by Jeremy Keith

Dynamic HTML: The Definitive Reference by Danny Goodman

Foundations of Ajax by Ryan Asleson and Nathaniel T. Schutta

Head Rush Ajax by Brett McLaughlin

JavaScript & DHTML Cookbook by Danny Goodman

JavaScript: The Definitive Guide, 5th edition by David Flanagan

Learning JavaScript by Shelley Powers

ppk on JavaScript by Peter-Paul Koch

The JavaScript Anthology: 101 Essential Tips, Tricks & Hacks by Cameron Adams and James Edwards