I had same problems with Outpost before, and no matter what steps I made to fix those problems, nothing helped. Outpost started to act like crazy sometimes... I contacted people from Agnitum, no one ever responded... the only thing that gave me back my internet connection was completely disabling Outpost.
I finally uninstalled it, removed every single registry key Outpost related, installed Sygate latest version (of course, freeware) and never ever had single problem with it. I uninstalled Sygate few weeks ago, just because I like to test some other products from time to time. Right now I'm back to ZoneAlarm freeware version and so far, it behaves as every good firewall should behave. It's unbelievable easy to use, especially for beginners, and gives you great protection. I'm also behind my hardware router/firewall, and it works perfect with ZA and/or Sygate.
Try one of those two, and you'll not regret. Of course, you have to completely uninstall Outpost and all traces of it in registry.
My recommendation is to go with ZA, especially 'cause I've noticed that you stated in your initial post that you have no clue about firewalls. ZA will give you great protection with minimal requested user interaction.
Cheers !