|What exactly are you trying to do?|
Physically connecting a Ubuntu box to the network is simple enough. If you use DHCP within your network to assign TCP/IP settings to clients, set the linux boxes NIC to "DHCP". If you use static assignments, then give it an appropriate IP within the same subnet as the rest of your network.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.