Here are some other DHTML related sites I find useful. If you're looking for a good reference, tutorial, or example, try these...

Development News & Blogs

The Daily Report
Much-needed standards-based advocacy from Zeldman, with many interesting links.
A List Apart
Magazine for people who make websites.
A community of website designers, who have written many interesting articles.
Simon Incutio
An interesting blog on all things Web-related.
Dave Shea's weblog; the creator of the CSS Zen Garden.

Reference / Tutorial Sites

REALLY comprehensive set of references on CSS/XHTML/DOM/etc. Bookmark this one.
QuirksMode (PPK's Site)
Lots of DOM/CSS compatibility resources and JavaScript information!
From the standards organisation, a series of free tutorials on almost all common web technologies.
JavaScript FAQTS
A massive database of JavaScript problems, ideas and solutions.
13th Parallel
Some excellent articles and standards-based code. A shame hasn't been updated recently.
A nice site, with a fair amount of IE-only code, but it has some neat techniques.
JavaScript Kit
Clearly arranged JavaScript tips and tricks, DHTML tutorials.
An excellent community site, with many scripts and articles.
Dynamic Duo
Good reference for DHTML in NS4 and IE4, but not updated for W3C DOM scripting. The original home of the DynAPI project.

The Horses' Mouths

MSDN Library
Microsoft's spin on DHTML, CSS and JS, well worth a browse. Look under 'Web Development' > 'Web Page Development', as well as 'Scripting'... this site is packed with information.
The Mozilla Project: Web Developers
Much info on DOM-related issues, a good part is the DOM Reference, an excellent introduction to DOM development.
Opera Specifications
Features supported by the Opera browser.

Send Me More!

I'm always looking for useful web development resources to link. So please empty your bookmark folder in my general direction!