Where can I find a free tool to monitor a child’s computer activity?

It’s not necessary that it blocks out pornography or other kinds of websites, but I just need it to send me regular e-mails showing internet activity, websites visited, computer screens at regular intervals, etc.
1) I want a free program
2) I want a program that e-mails me all that.

Any Free Tool Available For Squid & Proxy Logs Analysis in Linux ?

I have Linux (Fedora Core 5) Proxy Server Running In My Organisation. Proxy Server Has UserName & Password Authentication. I want Free or Open Source Tool So That I Can Log The Internet Activity Of Each User & Each Machine (With IP Addr.) In The LAN.
If You Guys Are Aware Of Any Such Free or Open Source Tool. Please Let Me Know.

Thanks In Advance.