If you have iOS 4.3 on your iPad, iPhone or iPod Touch you can easily stream media from iTunes on your computer. You will also need iTunes 10.2 or later on your Mac or PC.
Of course, your computer and iOS device will need to be on the same Wi-Fi network. Using this feature to stream media can conserve room of your mobile device for other content.
If you haven’t already turned on home sharing in iTunes, you will need to do so.
To enable home sharing in iTunes;
After home sharing is turned on in iTunes, you will need to activate it on your iOS device.
To enable home sharing on the iPad;
Now home sharing is active on your iPad, you can open the Video App, select “Shared” and stream rentals, movies, TV shows and podcasts from your computer.
To stream music, open the iPod app, tap “Library” and choose your library.