HOME NETWORK SET UP

I’ve read looking for an answer, but get tripped up when certain terms are used that make me think the set up is not like mine. I have two pcs running xp sp2, they are both connected with a broadband router (Linksys). They both currently enjoy an independent connection to the internet (did something right). I can ping them both with the firewall down. Currently, only one has a firewall on it which is the one I use to back up my data. I think they should both have one.

From what I have read all I need to do is in Network Monitor set up a “Trusted Zone” on both PC’s running CPF. I’m at work so I can’t play around with it. But is it fairly intuitive? Some discussions get pretty deep and I have no idea what’s being discussed. I apologize for the remedial question, just don’t want to muck up what I’ve gotten done so far…

Thank you in advance…