All of my systems, Windows, Mac and Linux have shares that are visible to one another on the network. SAMBA sharng is used, which is basically the Windows mechanism. Thus, you only need to have the 'source' and 'destination' switched on for any given fie access, the others are irrelevant.
The drawback with any file sharing however is that if somebody with a virus-infected computer ever gains access to your network, the file sharing can allow the malware to spread. For that reason should think very carefully about exactly what you share, and whether 'guest' access should be allowed (almost certainly NOT), and ensure that only the minimum subset of users are allowed to access each share.
Problem with above arises when sharing XP home edition, as it simply shares the entire folder with every computer, no login or passwords needed.