A developer's community exists at SiteExperts.Com where web designer's can find an exciting collection of DHTML effects, resources, and information to begin their learning. The techniques are well explained including the differences and solutions for Netscape and IE.
Online tools, a DHTML Diner, and interesting tutorials can be found in web reference's DHTML section. Regularly updated, with new columns every two weeks, this site is definitely worth the visit.
WebMaster Central's DHTML section features some of the best demos on the Internet and includes an award to outstanding design. Also includes tips, tutorials and other resources.
Jeff Rule's Dynamic HTML Site: cross-browser scripts, resources, and more!
Dynamic Drive: free scripts and components for both 4.0 browsers
DHTML Links : tips, tutorials, html editors, books, newsgroups
DHTML Pitstop: online scripts, resources