ok well that page didnt load up but ill try and answer your question as best i can.
Basically the thing you need to download are the drivers for the raid controller.these should have been provided by your omtherboard manufacturer, if not they will be able to be downlaoded from their site. if you cant find it give me your mobo manufacturer and model and ill find them for you. Okay so you need these drivers because, when you boot up your computer and install windows xp (im assuming its windows xp) windows wont be able to see your harddrive. Basically, the raid controller makes your two harddrives look like one harddrive (in striping), and therefore windows needs to know how to talk to your raid controller. this is what the drivers are for. During the windows xp installation screen (when the blue one first comes up after booting from CD), you need to push F6 to install these drivers.
Once that is done it will be fine.
Trust me, i know how you feel. the first time i tried doing a raid installation i was nervous, but it all went okay. jsut relax and youll be fine. any problems, just post on here.