Most important thing: nearly all firewalls are the same. I mean they all say that their firewall is the best, but they all use iptables. If you know all about iptables, you already know nearly everything about firewalls. And if you fire up your BT and type iptables on the command line you will see that it's included in (nearly?) every linux distro.
Just google for iptables:
Iptables Tutorial 1.2.2
If your "home FW software" doesn't allow iptables rules, it sucks