1. If you router is secure, enable sharing on the drives you want to share over the network. I would recommend making a folder specifically for this purpose since you don't need to share your whole hard drive with everything on it. You can do this from the properties menu of a folder/drive under the "sharing" tab.
2. Connect each computer to the router; if it has multiple ports then it?s probably a switch too. You will need Cat5 or above cable with RJ45 ends.
3. Find out the computer names, this is what each computer is called on the network.
4. Go to "my computer" and in the text field at the top, type in "//computer name here/" without the "" and replace it with the destination computer name. This is the easiest most direct way to the computer you wish to intend to share. "My Network Places" or "Workgroup" windows are worthless as windows has a "hit and miss" timing on when the computers are available on this level.