XHTML
http://www.xhtml.net/
Technology talks by Loïc d’Anterroches
http://www.freewebmasterhelp.com/
Learn the new language which is set to replace HTML, making sites compatible across a whole range of systems. (Free Webmaster Help).
http://www.sitepoint.com/
SitePoint.com - With a vast variety of web design tutorials and articles coupled with a vibrant and well informed community, SitePoint the natural place to go to grow your online business.
http://www.webheadstart.org/
Frequently asked Questions about XHTML (The XHTML FAQ).
http://xhtml.org/
This site provides information related to XHTML. Please visit W3Cs WWW site for additional ("official") information about the W3C Working Group on HTML which is responsible for developing the XHTML specification.