Ok, first things first.
Wireless card.
What kind of wireless card do you have? USB, PCI, PCMIA? What brand and model name.
You will also need the Windows drivers available.
After you get all of that, download ndiswrapper:
http://ndiswrapper.sourceforge.net/debian/
I think Ubuntu uses debian based packages but I am not sure...Unpack the folder and put it somewhere where you can get to it from the CLI (command line interface aka console).
Get that far first.