To update to the latest version, go to the Apple menu and choose Software Update to see if there’s an update available.
Choose System Preferences from the Apple menu on your Mac. Click iCloud, enter your Apple ID, and select the services you’d like to enable.
Want to use a different Apple ID for iTunes?
Open iPhoto or Aperture and click the Photo Stream icon in the left column. Then click Turn On Photo Stream.
To enable automatic downloads for your music, apps, and books, open iTunes and choose Preferences. Then click Store and select Music, Apps, and Books.*