Mozilla: Using Web Standards in Your Web Pages - A technote hosted at mozilla.org that describes how to upgrade a proprietary (DOM0 based page) to Web Standards. - http://developer.mozilla.org/en/docs/Using_Web_Standards_in_your_Web_Pages
IRT - Dynamic HTML Articles - Articles and examples focusing on layout and visual effects. - http://www.irt.org/articles/dhtml.htm
WebFX - Free samples, tested in IE5, Mozilla and Opera and articles about various widgets, scripts, and games. - http://www.webfx.nu/
EServer TC Library: DHTML - A collection of rated, reviewed online resources to help people who write DHTML user interfaces to websites. - http://tc.eserver.org/dir/DHTML
Whirly Wiry Web - Guide with questions and answers on DHTML, ActiveX, scripts, and neat net code. Focused on Microsoft Internet Explorer and intranet issues. - http://www.whirlywiryweb.com/
NetScript Technologies - Open standard cross-browser JavaScript DHTML components and tools for Web application developers - http://www.netscript.com/
Site Experts - Web development discussions and resources, emphasizing Dynamic HTML. - http://www.siteexperts.com/
DHTML Nirvana - DHTML, CSS, JavaScript and Graphics Tutorials from Eddie Traversa. This site is a free resource site for developers. - http://dhtmlnirvana.com/