There is no additional software required to connect computers with a hub/switch. This is simply the hardware used to make the physical connection. As you rightly say, a "switch" is more intelligent than a "hub" in that it sends data only to the correct destination IP address.
Once the computers have their physical connection, any folders and/or printers that have been "shared" should appear in "My Network Places" ("Network" in Vista) of all computers.
All versions of Windows have "File and Printer Sharing for Microsoft Networks" and "Client for Microsoft Networks" which manage the networking.