When editing skins and templates, you'll need at least some basic knowledge about HTML and CSS. This section provides some pointers to online tutorials and references:

• W3Schools: online web building tutorials (HTML, XHTML, CSS)
• CSS Panic Guide: links to various CSS resources
• Webmonkey: HTML Basics
• Webmonkey: Stylesheets
• Dive Into Accessibility: Online book, not really about HTML, but about accessibility and how to make your site more accessible.