TweakTown have an Internet Security & Firewalls Guide. Here's a snip:
"The Internet. It's something you depend on, something which you use as a hobby, something you use as a job or just something you use for leisure. But how secure is your Internet connection against hackers and spyware? Maybe you need a software or hardware firewall? Listen up as TweakTown tells you everything you need to know about this very issue!"