DHTML

Ajax: The Definitive Guide
$49.99
This book was pretty straightforward and clear in its explanation of the various pieces of Ajax. This portion of the book only comprises the first 200 pages though so if you're not looking for an Ajax cookbook this isn't the book for you. Also, this book doesn't go through the various Ajax frameworks in any depth.

DHTML and CSS for the World Wide Web, Third Edition
$21.99
All the Peachpit Press Visual QuickStart books are organized well and progress in an appropriate logical manner. The index for this book helps to quickly find the information you need. I build website's regularly and this book extended my knowledge. A good buy.

DHTML Utopia Modern Web Design Using JavaScript & DOM
$39.95
I agree with most reviews for DHTML Utopia; the book is middle level, leaving beginners in the dust but pros wanting more. It is, however, well written and contains very good code and coding standards. If you are not completely new to JavaScript and DOM scripting, but would like to learn more and make sure your code is up to today's standards, then this book is for you. If you are very familiar with web scripting and/or have been writing your own unobtrusive client side code then go with a more detailed book.

DHTML and CSS Advanced: Visual QuickPro Guide
$29.99
I was greatly disappointed with this book. I have bought many other visual quickpro books which have been great.

This book is not advanced. The examples in this book do not separate content, presentation and function.

Javascript should be separated from the content of the page, not mashed into the (X)HTML as was typically done in early web sites. The javascript hooks in the code examples are invariably hard-coded into onclick=".." attributes. While that may work fine at first, just try updating pages full of onclick attributes and you'll be looking for a better way.

CSS should be used to separate the presentation from the content of the page as much as possible. It seems that the author has 'divitis': there are so many nested divs in some of the examples it's hard to follow the markup.

The book gives lip service to accessibility, but does not follow the concept through: many of the examples will not degrade gracefully in non-javascript enabled browsers. Dynamic html pages _can_ play well with all browsers: this is advanced javascript. If you follow the examples in this book, however, you'll be discriminating against a large part of your audience.

You will get better information in:
For css:
CSS Mastery: Advanced Web Standards Solutions
Web Standards Solutions: The Markup and Style Handbook (Pioneering Series)
For javascript:
ppk on JavaScript, 1/e (VOICES)