Hmm. Tricky question. And in the interests of full disclosure, I work with tech services at work, but my skills run more towards library database management than this sort of thing. Personally, I'd imagine it'd be simpler to just play online games on your computer, considering that you already have the fast connection and the Playstation 2 is not really designed for online game play. (That's what the E3 will be for if Sony ever gets around to releasing it.)
That said, I found a few places for you to visit in your search for instructions:
http://www.computing.net/networking/wwwboard/forum/26778.htmlhttp://www.computing.net/networking/wwwboard/forum/27914.htmlhttp://eu.playstation.com/pdcf/index.jhtmlGood luck!