If you are using Fedora Core 3 as your profile says, do the following:
1. Open a terminal Window
That should bring you a menu similar to what you see in Windows. Simply highlight your card and click "Edit".
At the middle of the window there will be a area called "Statically Set IP address" check that box and simply input your information as you would on the Windows Machine.
Next, click "Ok" on that window and click "File...Save" on the main window.
That should do it.