Open iTunes and select "Home Sharing" in the viewing pane. Choose "Advanced" from the top menu and "Enable Home Sharing" if it does not appear in the viewing pane.
Type in your iTunes or App Store username and password when prompted.
Click "Create Home Share." Enable home sharing on all of your home network computers, and fill in your iTunes or App Store login information on each network computer, and click "Create Home Share."
Go back to the computer you started with in Step 1, and search for the iTunes library you want under "Shared" in the viewing pane. Click on it, and double-click a file to listen to a song or watch a video.
Click "Settings" and specify file types in order to transfer files from another iTunes library on your home computer network to your computer. Click "OK."