so all I need is my ds lite, a router (linksys recommended) and the Win2ds server.
then I just set up wifi and it works then.
But do I need anything else like an R4, and does the router need to be connected to the internet if your not using a linksys?

you need a ds, not necesarily i lite, a phat will do the job just as well.
you also need a flashcard, such as an r4, a wireless network. doesnt have to be a linksys either. and the router doesnt have to be connected to the internet if your using Win2DS, you just need to have your computer and DS both connected to it

Can you use the games n music card for this?