Six Things First-Time Squid Administrators Should Know — ONLamp.com
Some hints on installing and managing Squid.
#webcache
Do-It-Yourself Caching: Squid 2.3
Do-It-Yourself Caching: Squid 2.3
A little old, but seems to be a pretty detailed tutorial on getting Squid running.
mnot
Mark Nottingham’s site. Smart guy into HTTP/Web Services/REST/Caching/feeds/etc.
Squid 3.0 Configuration Manual – Contents
Squid 3.0 Configuration Manual – Contents
Detailed reference manual on all the Squid configuration directives.
Squid 2.5 Quick Start Guide
Brief intro to get started with Squid using some really basic settings.
Apache module mod_proxy
Details on the Apache module for running as a proxy/cache.
Cache Tester
A page that allows you to generate pages with defined expiry/last modified headers to test a caching configuration.