Contents:
(Items in BOLD are most recommended)

A Beginner's Guide to HTML

This is absolutely the first place you should start, even if you're using HTML editor software. I think it's a good idea for you to understand what the HTML tags and options mean. Some editors use them in inappropriate ways. This document is also nice because you can view it online in pieces or print out the entire document.

A Beginner's Guide to URLs

So, you want to make a Web Page!

HTML tutorial from Joe Barta

Introduction to HTML - by Eric A. Meyer

Introduction to HTML - by Ian Graham

How to write HTML files

Intermediate HTML

Netscape Extensions to HTML 2.0

Netscape Extensions to HTML 3.0

Hagan's HTML Help Library

This may not be available for long, so read it while you can.

How do they do that with HTML?

An easy to read guide to the most common questions.

Guide to HTML Commands

Very comprehensive index, split up in multiple pages

D. J. Quad's Ultimate Tag Reference List

Less comprehensive but easier to navigate

HTML Quick Reference Guide

Not quite as comprehensive, but it's all on one page. This is probably better if you're not exactly sure what you're looking for. Much more of a "quick guide."

Quick Guide to HTML Tags

A four page guide that's a good introduction to tables and special characters.

Bare Bones Guide to HTML

HTML Documentation

Otmar's List of HTML tags

HTML Quick Reference

Special Characters

HTML Special Characters: iso8859-1 (Latin-1) table

Making sure your pages are accessible to those with disabilities

Accessible Web Page Design - in English & French

Contains a list of design issues and how each is handles by various special browsers.

Accessibility Issues on the Web

A very comlete list of suggestions for designing accessible web sites. There is less discussion of the problems that can occur if you don't follow these guidelines.

Designing Accessible Websites

This is a list of links for further research on this issue.

Unified Web Site Accessibility Guidelines

This is a very comprehensive document containing methods to diagnose and correct common accessibility problems.

WebABLE

The authoritative Web directory for disability-related internet resources. Contains the latest news, websites, conference listings, and a very large library of articles, white papers, projects, and online journals.

World Wide Web Consortium's (W3C) Disabilities Developments

This site contains the latest news and research about accessibility issues on the WWW.

Web Access Symbol Now Available

This image may be freely used by webmasters to denote that their site contains accessibility features to accommodate the needs of disabled users.

Writing Accessible HTML Documents

A list of design guidelines, each with reasoning, implementation details, and results before and after the change.

Creating Killer Web Sites

David Siegel has some really interesting ideas about web design. It's worth a read, even if you don't agree with him. The section on browser offset is particularly useful.

Tips for Writers and Designers

Same guy (Daivd Siegel) - more ideas

Dmitry's Design Lab

Contains very well-written monthly articles about effective web design from the graphic design perspective.

Yale C/AIM Web Style Guide

An HTML Style Sheet

Directed toward commercial and large information sites.

Web Developer's Virtual Library: Style

Web Pages That Suck

Learn good design by looking at bad design. Basically, this site is a Web design course based on learning from others' mistakes. This page teaches with bad examples the don'ts of Web publishing.

HTML Bad Style Page

Top Ten Ways To Tell If You Have A Sucky Home Page

Sucky to Savvy

This is the follow-up to the above top-ten list. It includes techniques for avoiding common problems. Both these sites are well worth a visit.

Making the Most of the World Wide Web for Your Organization

Style Guide for Online Hypertext

Composing Good HTML

See also: HTML Tools, further down the page

Table Tutor

Tables in Netscape

Design Ideas for HTML Tables

The problems with tables

The HTML3 Table Model

Very advanced -- read this after you really understand tables.

Frames Tutor

The Art of Frames

Frames: An Introduction - Netscape

Targeting Windows

Useful in conjunction with Frames

THE Netscape Frames Tutorial™

Form Tutor

CGI Manual of Style

The CGI Resource Index

An amazing resource. Includes programs and scripts, documentation, books, articles, programmers and job openings.

Matt's CGI-Script Archive

Mosaic for X version 2.0 Fill-Out Form Support

Decoding FORMs with CGI

FrameShop

TableMaker

The Table Sampler

HTML Tools from the University of Colorado, Boulder

Why Validate Your HTML

A Kinder, Gentler HTML Validator

Checks your HTML code for errors general errors based on document type.

Doctor HTML

This tool checks for different types of errors, including document, table, and form structure, spelling errors, image size and specification, loading time, and link viability. I am completely amazed by this online resource.

Web Site Garage

The "Tune Up" area checks any URL you enter for various problems including load time, link viability, spelling errors, search engine ranking, and HTML design. It's got a very different layout, and analyzes aspects of your site that many other validation tools don't. It also has a "GIF Lube" area where you can reduce the sizes of images via GIF and JPEG compressions.

Bobby--Web Site Accessibility Verifier from CAST

This validator allows you to check compatibility with lots of different browsers (older and newer versions). It also checks to see whether your page is accessible to those with disabilities.

NetMechanic

This site contains 2 tools, one for checking HTML code for errors, based on browser compliance, and the other checks external links for errors. Nice features of this site include the ability to run jobs in the background and have it e-mail you when complete and the ability to search a page or an entire site.

WebTechs HTML Validation Service

Webreference.com

An incredible resource for design and programming.

The Art of HTML

Nicely laid-out, includes reviews of HTML pages.

The Web Designer

Web Mastery Resource Lists

Help sites, broken down by topic.

HTML Documentation

Yahoo - HTML

Yahoo - Page Design and Layout