Instructions
Turn on your Xbox 360 and allow the main dashboard menu to load. You do not have to be playing a game to connect a microphone to your Xbox 360.
Turn on your microphone.
Press the "Connect" button your Xbox 360. This is the same button you press when connecting wireless controllers to your console.
Press your microphone's "Connect" button. Watch both the microphone and the Xbox 360 for a solid green light to illuminate. This indicates that the headset microphone connection has been successful. Speaking into the microphone will allow you to hear your voice on the console.