I have recently set up wireless in VL 5.9. It's very possible that your wireless hardware is already supported but just needs a jump start. What worked for me was to go into Wifi-Radar, select Preferences, and check the box that says "Ifup Required". Also check "auto-detect wireless device" if it is not already checked. Once I did that, I could see my wireless network as well as others nearby while still in Wifi-Radar. Then I set up encryption, etc. in Wifi-Radar and clicked connect to make a connection.
If you look at my reply to the HowTo at the link that rbistolfi sent you, which as of now is the very last one on the 2nd page, there is info there on how to have the connection start automatically after booting. My version only covers WEP encryption, however.