Maintainers and creators of many of the web standards.
Lots of helpful information on Microsoft driven server and client technologies.
This has many free sources, references and tutorials for DHTML writing. A
very good ressource for things like: creating dynamic menus, drag and drop
with Jigsaw Puzzle sample etc.
Good tutorials. Some cover complete W3C standard's in a little easier to read fashion.
Links and info to cascading style sheets.
"...focus is Cascading Style Sheets (CSS)... a useful source of information, examples and links to other external resources."
The Active Server Pages Frequently Asked Questions
Huge collection of old browsers at browsers.evolt.org.
The official site of the programming language by Sun Microsystems.
Search this discussion group postings archive if you're running into programming