this one will show you how to share your itunes library over a network [a local network, like your home wifi network =]

first thing:

authorise all your machines with the same itunes store account.

then:

• open itunes on the machine where your library is [ill call it the main machine form now on]
• goto preferences > sharing
• tick ‘share my library on my local network’
• pick the things you want to share [probably your entire library]

then: