How to play music from iPod in Macbook iTunes?
That feature is only available on iOS 5 for the iPad, iPhone, and iPod Touch. If you have one of these devices with iOS 5, connect your device via USB, open iTunes. After your device shows up, under the primary device tab (should default to it), towards the bottom, there will be a checkbox to "Sync this i(Phone, Pad, or Pod) over Wi-Fi." Check the box, and you should be set.

You must be on the same Wi-Fi, and have your computer on with iTunes open for it to actually sync in the future.