Infracstructure upgrade

I have four Penthium 4 windows 2000 PCs, two Apple Mac G4 and and one PIII PC. All machines are currently stand alone. I want to set up a network with a file server, windows/linux and I have made some form of awareness for users to know what a networked systems are about. I however want to have a questionare. Can someone help me with what kind of questions I’ll need to ask? I do not wish to change the Mac.