How to Setup Simple Iptables Rules

Iptables sometimes very interesting to learn, but you must be patient because it's all about commandline, (don't talk about Shorewall, Guarddog, etc) and no GUI. You will always forget the command when you need to setup a simple rules like mine. I'm forgot the command to allow Webmin and Squid port. My suggestions here, always practice your Iptables command, don't lazy. Here a good howto about basic iptables setup http://www.howtoforge.com/linux_iptables_sarge