Should only need a few things
1. a wireless router
2. a wireless adapter for the Xbox
3. The security setting from your router to input into the Xbox if you set up a secure network (which you should)
TKIP or AES
Encryption type (WEP, WPA, WPA2 and so on)
and Passphrase if one was set up.
Other than inputing that into the connection settings on the xbox there should be nothing else needed.