http://www.wiichat.com/nintendo-wii-...ion-guide.html
I'd suggest looking there. The DS is fairly easy to set up. First you need to put in a game that is an online game (Tetris, Mario Kart, Animal Crossing, etc.) and click the WiFi/Online option for the game. Then there should be an option for WiFi Setup, click that. Search for an access point, confirm it is good and you are alright. If you still have troubles just search google or something.