This is wrong forum you're posting this thread on (LQ Suggestions and Feedback isn't right, I'd try some networking forum instead).
Anyway, if native drivers existed for your wireless card, you would just make sure it powers up (on laptops this is usually achieved by pressing a special button or a key combination) and use some network manager program (for example Gnome's network manager or on KDE the Wireless Assistant) to set the information you need to connect. If this doesn't work (you know the programs, but your card isn't functioning), you'll need to know the exact type of the card ("Broadcom 4318" for example). Then you would obtain Windows drivers for it (a .inf file that is for that card model), if you need to resort to this method, and install (or rather make sure it is installed) a program called ndiswrapper, then use it to install the .inf driver file. I'm not repeating the whole procedure here; there are howtos, examples and a lot of threads about installing and using ndiswrapper here at LQ and all over the net; using Google you may even find a step-by-step howto for your distribution (you did not mention which Linux distribution or version you are using, nor the model of the wireless device; you should tell that kind of stuff when posting, or add the distribution to your profile so it's visible).
Take a search for ndiswrapper and see what you get; it should be fairly easy to get (using your distribution's package management program) and use.