dont read nvm

ok ijust asked about this yetrday but I ahve another question I am going to get the wireless adapter for my xbox 360 when i get it do I just plug it in the back of my xbox and dont I have to hook something u to my computer for it too? and also im reading about ti and it says its compatuble with the 802.11a, g, and b protocols for Xbox Live...what does that mean and finally i have an an original xbox I want to get hooked up is there a router that will hook up and old xbox and another computer on the same router and if there is which one would be best? THANKS!