Is your xbox modded? If not follow my guide at the top. Then you gotta decide what version of linux you want for your xbox, go to
www.xbox-linux.org (i think, or go to souce-forge.org and type in xbox-linux), and u can dl it for free, then all you gotta do is install it, what i did was i xfered it over by ftp then executed the .xbe and it installed :P You also have to have a usb mouse and keyboard, or the converters so that you can use ps2 mouse and keyboard on usb, then you gotta add a usb port on your xbox, or convert one of your controller ports to usb. Your choice really. What i did was i took a spare break away cable, cut it up, and spliced it with a usb extender, after that i use a usb hub to connect more things :P