I have 2 computers on my home network and I know their internal IP numbers (192.1…). I also know the IP of the server.
Are there any specific rules I should configure?
I have attached a screen shot of the rules that are set up already.
[attachment deleted by admin]
First, i’m no expert, but my network works fine…
So, I’m gonna ask you a few questions here, even if they seem stupid… 
It looked like you had defined a trusted zone and a trusted network, so it should work.
Have you done this on both computers?
Have you used the same name on both computers, on the trusted network/zone?
Have you made a network in windows on both computers with the same name and settings?
I used the same name as in CPF’s trusted zone.
Have you done this before or after setting up CPF?
Have you allowed filesharing/printing? Restarted computers?
Does your router give the computers a static ip?
If your router has 192.168.0.100
and your computer1 192.168.0.101
and your computer2 192.168.0.102
I take for granted that your trusted zone is 192.168.0.100 - 192.168.0.102
Just check through these things once more, and we will se if it works.
If not, just post here again, and we will continue to help you until it works… ;D