io non me ne intendo, ma in rete trovi risposte:

http://serverfault.com/questions/224...-document-root

http://joomla-and-more.com/2009/10/2...-under-ubuntu/

http://forum.it.altervista.org/linux...a-var-www.html


http://www.uielinux.org/uie-guide-e-...ick-guide.html

p.s.
http://wiki.ubuntu-it.org/Server/Web...erver%2FApache