Unable to share resources.

I recently installed, configured and successfully connected my win2k pc and xp laptop through a wireless firewall router to access the internet.
Unfortunately, i am unable to share the resources of the pc to the laptop and the other way round.
Both have the same workgroup name, but cannot connect to each other.
I’d like to be able to share the printer (currently connected to win2k pc) with the laptop through the router and also files and folers on the pc and the other way round.
How do i do this?