Official HTML 4.0 specifications
This is the mother lode. All the tags, all the attributes, all the legal/illegal junk, everything you need to master HTML 4.0.. but very confusing to the complete newbie. Get some experience first, get comfortable with the terminology, then tackle it.

Advanced HTML tutorial
This is where you should go if you want to learn about frames and other HTML stuff that isn't for newbies. Master the stuff I provide first, then go here. :) Self-promotion, YEAH! This does start from the beginning, but it's a lot more in-depth and it's just wonderful.

Official CSS specs
The official CSS specifications, by the World Wide Web Consortium. Like the official HTML specs, these can be tricky to follow - they're written by pros for pros, and no matter how they try to tone it down so anyone can read them [it is in their best interest], it's a little hairy. Once you get used to their terminology, you should be fine.

CSS tutorial
A nice beginning tutorial in CSS, from Pageresource. Explains everything clearly and concisely, very user-friendly. You'll also find links to other CSS resources here [as well as other web design, HTML and JavaScript resources, as well].

Official JavaScript specs
This is a collection of pages by Netscape [the developer of JavaScript], that has everything you ever wanted to know about JavaScript, but were afraid to ask. Programming knowledge or some experience with JavaScript is required when trying to read this - it's the Developer's Manual to JavaScript 1.3. Ouch.

JavaScript tutorial
This comprehensive tutorial is very easy to follow and is structured in the way of a `class.' And you don't need to be a programming genius to follow it.. Heck, you don't even need to know math! [which is, by the way, very useful if you're going to learn JavaScript]

Charsets and languages
Lists all existing character sets [refer to the META tags section of my HTML tutorial on how to use these in your pages] AND all the two-letter language codes.

Colours
A web-safe colour-chart [lists colours that will look the same in all browsers]

Free Stuff
A collection of free stuff for the web designer and the surfer alike. You can spend HOURS here and not get bored. Unless you're looking for something specific, in which case you'll most likely find it very fast.