Websemantico.org
http://www.websemantico.org/

Senso Comune
http://www.senso-comune.it/

W3C Semantic Web
http://www.w3.org/2001/sw/

The Semantic Web: an introduction
http://infomesh.net/2001/swintro/

Semantic Web Resources
http://www.xml.com/semweb/