CSS

Cascading Style Sheets - a mechanism for controlling aspects of the layout and look of a webpage. Written like short program modules, the code can be either embedded in the same page as the HTML or created separately and imported to the pages.

Resources in this category:

24 Ways - web design and development articles and tutorials
http://24ways.org/

An advent calendar of web development tips and tutorials from professional web designers. Contains articles and tips for those building Web sites.

CSS Basics
http://www.cssbasics.com/

Exactly what the title says - a good introduction to the basics of using Cascading Style Sheets (CSS) to control your website's look.

DevGuru - A Developer's Resource
http://www.devguru.com/

"DevGuru is a premier developer's resource featuring a comprehensive quick reference for ASP, JavaScript, Jet SQL, Style Sheets, and VBScript, free online tutorials and product demos, and useful products - all of which can be downloaded." Site includes "'Quick Reference' documentations and 'How To' manuals, that deal with a wide variety of topics of interest to developers and computer programmers."

HTML Source: HTML Tutorials
http://www.yourhtmlsource.com/

Presents step-by-step tutorials for creating your own website. Covers HTML, CSS, and JavaScript. Includes useful information on the basic principles of web design and web accessibility.

IPL Kidspace: Learning HTML
http://www.ipl.org/div/kidsweb/

Designed to teach kids the basics of HTML and CSS, but a good resource for any beginner.

The Man in Blue
http://www.themaninblue.com/experiment/Technicolor/

Useful tool for generating color schemes. Generates CSS code using the colors you select for you to copy and paste.

MSDN Library
http://msdn.microsoft.com/en-us/library/default.aspx

Essential information for those developing in the Microsoft environment, using Microsoft tools, products, and technologies. Includes documentation, tutorials, and sample code, and reference materials.

Open Source Web Design
http://www.oswd.org/

Download a free, open source web template for your own website and customize it as you like using HTML and CSS.

QuirksMode
http://www.quirksmode.org/

QuirksMode includes tables that provide an overview of browser compatibility information with respect to CSS and JavaScript capabilities as well as W3C standards.

SitePoint
http://www.sitepoint.com/

Compilation of articles and blog entries on a variety of web development topics: HTML, CSS, web design, JavaScript, Flash, server- and client-side coding, and much more. Information ranges from basic to advanced. Also includes handy CSS, HTML, and JavaScript references.

W3Schools Online Web Tutorials
http://www.w3schools.com/default.asp

Everything you need to design and produce a website. Comprehensive, step-by-step tutorials cover all steps of website creation for all levels of developers, from beginner to advanced. Includes links for validating the code you write to make sure it's compliant with the latest standards.

Webmonkey
http://www.webmonkey.com/

This "How-to Guide for Web Developers" contains tutorials and reference materials for those building Web sites. Covers topics such as e-business, design, HTML, JavaScript, PHP, databases, graphics and fonts, multimedia, and more.

WebPelican
http://www.webpelican.com/

Contains tutorials and resources for Internet programming using XHTML, CSS, XML, and Java.

ZVON.org
http://zvon.org/

Contains "references, tutorials and interactive tools focused on XML technologies (XSL, CSS, XHTML, ...)"