This guide will walk through the setup and installation of Debian GNU/Linux and Squid proxy. Optionally, DansGuardian may be used in addition to provide URL blacklisting and content filtering.
Read it here
The setup process contains the following steps:
Install Debian GNU/Linux
Install our proxy and content filtering software
Configure the Squid Proxy
Configure the DansGuardian content filter
Install and configure some sort of logging/monitoring solution