I've installed squid3 on my Ubuntu 12.04. I changed the http_port to 80. When I type 10.1.1.103 in the "The requested URL could not be retrieved" from squid. Do I have to run Apache as my web server or squid has a web server itself to run the web files? I am a little bit confused here. I am asked to setup squid on top of apache but I can't find the way to integrate them.
You have to use apache (or any web server, but squid is not a web server nor has any). To run it you need to configure apache on port, that would be asked by squid. That's mostly all.