What router do you have?
If it is a simple internet router, then it will have 4 ethernet ports on the back. You plug in the one computer to one port, plug in the other computer in another port. Use straight cables, not crossovers.
To allow file sharing and printer sharing between computers, right click "My Computer", go to "properties", then the "Computer Name" tab. Then click the "change" button, and in the "workgroup" box, enter a name for your network. This has to be the same on both computers.
For a multiplayer LAN to now work, simply start up the game of choice, create the LAN server (which obviously varies from game to game) and then make sure the windows firewall is not blocking it. It will be if you have not allowed it. Then check the list of servers to join on the other computer, and it should be listed there.
That is about as complicated as it gets, it's fairly simple to do.
If it is a simple internet router, then it will have 4 ethernet ports on the back. You plug in the one computer to one port, plug in the other computer in another port. Use straight cables, not crossovers.
To allow file sharing and printer sharing between computers, right click "My Computer", go to "properties", then the "Computer Name" tab. Then click the "change" button, and in the "workgroup" box, enter a name for your network. This has to be the same on both computers.
For a multiplayer LAN to now work, simply start up the game of choice, create the LAN server (which obviously varies from game to game) and then make sure the windows firewall is not blocking it. It will be if you have not allowed it. Then check the list of servers to join on the other computer, and it should be listed there.
That is about as complicated as it gets, it's fairly simple to do.