I got this dedicated server running CentOS 5 which I'm using to host several websites distributed among 10 IP address.

I need someone to teach/guide me through the process of installing and setting up Squid so I can use as many of those IPs as I want for the proxy server. For example, let's say the server got 5 IPs:
IP1
IP2
IP3
IP4
IP5

If I connect to (as an example) IP2ort 8580 I want remote sites to see that IP2 is the one opening the connection. Same thing if I connect through IP4 or IP5, etc.

In other words, just one Squid installation should be able to service every IP added to its list.

I just need a mini guide with every step I have to follow, command to run and file to edit.

As far as I know, this is really easy to do but I don't want to do it by trial and error and risk screwing something up and taking down my sites with it. So I'd rather have an expert tell me exactly what to do.