NoobProof is a firewall configuration tool for Mac OS X .
NoobProof has a list of services. Each service can be allowed or blocked. You can also selectively allow or block specified hosts or subnets. You can add or remove services from the list, and you can create new services.
Very easy, just follow the 5 steps how-to in the application help.
You can also tune bandwidth, manage black lists and create self-configuration tools called injectors. The first time you launch NoobProof the Wizard will help you configuring the Mac OS X firewall.
NoobProof is a frontend for ipfw. NoobProof is free software. If you want, you can donate using paypal. Thank you.