ok i wanna go online with my ps2, am i gonna need a router to have my ps2 and computer be online at the same time?
Or you could probably setup your computer as a bridge, and use Internet Connection Sharing built into Win98 and later. If you are planning on adding another laptop, or desktop soon I would suggest getting a router, as it is an easier setup for that. But if you were going to use Internet connection sharing you would need to have a crossover cable, two free Network Interface Cards in your computer and Windows 98SE or later. You'll connect your ps2 to your computer with the crossover cable, and then share your connection using Internet Connection Sharing. I hope this helps.
A router is a good way too though, in case you ever decide to connect more than one console to the internet.