First of all you need a xbox 360 wifi adapter (plugs into xbox) Second of all you need a wifi network adapter (goes from outlet to adapter) third of all you need so set up the internet settings in...
Okay so assuming that you already have the console all hooked up to your TV and the power set up. Once you turn on the console you will have the Initial setup which should automatically set you up....
as far as i know there is no longer xbox live for the original xbox if you want xbox live you have to get a 360 this is how Microsoft screwed over alot of people