Here’s a list of some JavaScript books:

• Pro Javascript Techniques by John Resig - amazon.com
• PPK on JavaScript by Peter-Paul Koch - amazon.com
• JavaScript: The Definitive Guide, 5th edition by David Flanagan - amazon.com
• The JavaScript Anthology by James Edwards and Cameron Adams - amazon.com
• Beginning JavaScript with DOM Scripting and Ajax by Christian Heilmann - amazon.com
• DOM Scripting by Jeremy Keith - amazon.com
• Bulletproof Ajax by Jeremy Keith - amazon.com

Personally I spend a lot of time with The Definitive Guide.