Jeff Rule, Senior Interactive Web Developer at Discovery Channel Online, has written an introductory DHTML book for developers. The book explains the many techniques he uses at Discovery and demonstrates at his RuleWeb site. It explains the various aspects of DHTML in easy to understand language. Compatibility techniques, the DOMs, and CSS are all covered plus code for rollovers, popup/out menus, drag and drop, and animations and timelines. He also previews upcoming features in the new version 5 browsers.

Dynamic HTML - The HTML Developer's Guide
Jeff Rule
Addison-Wesley, 1999. $39.95
ISBN: 0-201-37961-9