dansguardian, squid and iptables

yes DaLight, well it serves what i wanted to happen. the basic, block some sites not appropriate for the kids. we recently setup 40 computers in our lab, all had been given access to the internet so i did some googling about content filtering and after trying some beta versions of net nanny-like softwares, i found dansguardian more enticing since i wanted to learn more about linux.

i am now trying to grasp the concept of firewalling using the iptables.

so guys! you are all a big help!