How to set up Wi-Fi for iPod Touch at home?

I'm a computer techy, but with this whole wi-fi stuff I'm LOST!! Okay. I have a SpeedStream 5100 Ethernet ADSL Moderm router thingy. I hope I'm explaining it right.. Its with the whole SBC Yahoo thing.. (If that helps!) I want to know how I can step up me iPod.. PLEASE HELP!