Writing HTML A tutorial site for anyone wanting to learn the basics of html coding. Still useful and popular after 12 years.
HTML5 Rocks A how-to and resource guide on HTML5 for programmers, developers, and web designers. You can watch a slideshow and play with the HTML5 features, tour the step-by-step tutorials, view samples to reuse on your own site, etc.
Index DOT Html An advanced HTML reference guide and covers all HTML tags and attributes providing definitions, usage and examples. Very handy site.
Draac.com Draac.com bills itself as a complete guide to html. The site has a simple, appealing interface with a lot of good tutorial info as well as links to great online tools.
Quality Assurance ToolBox Quality Assurance ToolBox at the W3C Consortium offers a suite of validators that you can freely use. Includes a markup validator, css validator, xml validator, a log validator and more.
HTML Code Lab Primarily an HTML tutorial site but, if you take a closer look, it also offers free buttons, backgrounds, cgi scripts and more. This site is packed with 120 pages of useful information.
The Web Design Group Offers material on a wide range of HTML related topics. WDG is basically a reference site that covers the basics of HTML. It also offers online tools, web authoring FAQ archives, an HTML Help BBS and more.
Dynamic Drive An excellent source to obtain free, original DHTML scripts and components to enhance your web site. Over 12 categories of scripts to choose from, plus online wizards, FAQ's and pointers to other great webmaster resource sites.
Computer Hope.com A detailed list of HTML commands, with examples, which can be used in web pages to change text, add various features, and apply different effects.
ActiveJump.com A HTML tutorial site. If you're looking for a solid information on the basics of HTML, this is a good place to start. Covers all the major HTML areas and provides helpful examples of usage.