These are the links I would take to a desert island.
Everything, all-in-one sort of sites
Builder.com (part of C|Net)- This is the clear best of the bunch; it has both great design and great information. Builder Buzz is an excellent discussion board for web-building.Webreference (part of Internet.com) - A notch below Builder.com for info and layout, it's still good.
Webmonkey (part of Hotwired) - Hotwired is more of an almost-everything site than a complete reference, but when they explain a technology, they do it well, without techno-boosterism
Devhead - (part of the Ziff-Davis web sprawl) - Badly designed repackaged information from great authorities. I would look here last for anything, but I would look.
HTML code references
Web Design Group's guides to HTML - This site lists HTML codes both by where they are used in a document and alphabetically. (www.htmlhelp.com)w3c - These are the guys who wrote the book on HTML. Stuff here is pretty dense, but when you've got a really specific question there literally is no higher authority.
Graphics
Lynda Weinman's site - good information and great links on graphics issuesClipart
Microsoft Site Builder - I assume there's still clipart in there. There's also a lot of promising other stuff, but I never have the patience to wait for the bloated page to download.The Mining Company's Best of the Web Clipart guide
Javascripts
Javascript Made Easy
The Javascript Source
Cut and Paste JavascriptReviews and more sites on the Javascript page.
Forms
Response-O-Matic - This is the best of several free-hosted formmail scripts, which allow users to submit information in a form from your web page and have it mailed to you.The Free Site - This site lists several other formmail script hosts, and lots of other free WWW-development-related stuff.
Design and usability
Useit - Jacob Nielsen is the acknowledged expert on web site usability. You could just about skip everything else on this page in favor of useit.Creating Killer Websites - The web site for the best-selling book on web design.