...Wireless Network Adapter Xbox 360.? you dont need extra wires like ethernet wires right?
so if you you just put the wireless network adaptor in your xbox 360 you could join xbox live and play online?

You won't need any extra wires or anything, but form my experience wireless networking is less stable than ethernet. they lose connectivity randomly and often. I'm not sure if it would run any faster, I doubt it, as it all depends on you Internet connection. and the positive is that there is very little set-up, no drilling holes in your floor to run the ethernet cable through.

Your gonna want to stick with ethernet. It's a hell of a lot faster and you won't experience as much lag, therefore you won't get as much criticism from other players. But wireless does allow for you to have less wires. If you want speed go with ethernet, if you won't organization and simplicity (although setting it up might not be so much of a picnic) go with the wireless adapter.

like anything else, its always better to use wire, but if you don't have the wire or it's too far away from the hub, wireless will work. If you use the wireless adapter, you don't need the ethernet wire.