do you mean you are adding new hardware? or do you just want to configure the card?
To see if the lan card driver is working fine, you could use either ethtool, or mii-tool
Code:
mii-tool eth0
OR
ethtool eth0
If you can see some sensible stuff on your screen (like "Link Detected: Yes/No" on the last line) it means your LAN card is working fine.
Then you could run a tool like netconfig to configure the IP address on the interface. (if netconfig is not installed, you could use ifconfig as well)