All you need is a switch if you are planning on using Windows to manage the network. You can also use a router. They have certain advantages (that you probably don't care about).
Plug all your computers into the switch. Boot them up. Windows should automatically find the network connection. A little icon may appear in your system tray telling you that (or it may not, depending on how you have the settings set).
Run the home network setup wizard on one computer (open My Network Places and it should be a link on the upper left side task list.)
Tell the wizard you have no internet connection. You can leave the workgroup name set to the Windows default (MSHOME), since you are not connected to the internet. It is better practice, however, to change it (in case you connect to the internet down the road).
Once the wizard has run, click the option where the wizard asks if you want to save the setup to run on your other computers.
Then, take the media you just saved the network setup on and run it on the other computers.
If you don't have removable media or don't want to bother with it, then just run the wizard on the other computers, making sure you answer the questions the same way (except for the computer name, of course) and use exactly the same name for your workgroup.
As to communicating among the computers, that depends on what you want to do. If all you want to do is share files, just enable sharing on the folders on each machine you want to other machines to have access to. You can then find them in My Network Places on the other machines.
first straight forward attach those computers to the switch.start those computers.Give all the computers a different ip addresses and after that type ping command in the start-run box.for ex-ping 192.168.10.10(this address should be the address of the other computer,to find out if they are really connected to the network with each other to share the information,if they start pinging without any error,then share a folder(containg a file inside it) from one computer and try to access from other computers.
how to access from other computers?
double click on my network place-entire network-then u can see the computer name of all the computers inside the network,double click the computer name and the shared file is shown.