[H-GEN] Restricting web site access

[David Duffy]

Hi everyone,
What is the best way to restrict web site access on a "per user"
basis with Windows XP machines going through a Debian proxy?

The browsers used are both IE and Firefox. IE can have settings
to approve or block certain sites but Firefox doesn't seem to.

Googling gives the impression that the Debian box is suitable for
this for of use but I'm not sure of how to start off. Blocking based
on the domain name may be usable but can this be done per user?

Another thing I'm considering is content based internet filtering.
Does anyone have any pointers on this? Something that's proxy
based would be good so that it can't be disabled by Win users.
David...