This will show you how to connect Xbox 360 controller to Macintosh
Step 1: Get Microsoft Wireless Receiver
You will need the wireless receiver if you use a wireless xbox 360 controller. If you have a wired xbox 360 then skip this step.
Here is the link for wireless receiver on amazon.
Step 2: Get the Driver
You will need this driver or else the receiver will not recognize the controller.
Here it is.
After you have downloaded it and installed it. Go to Systems Preferences.
Step 3: System Preferences
Go on systems Preferences.
Step 4: Xbox 360 Controllers
click on Xbox 360 controllers.
Step 5: Base for Controller
Connect your receiver to mac and then connect controller to receiver.