How to Back Up Your iPhone to iCloud
You used to be able to back up your iPhone content using only iTunes, but with Apple’s introduction of iCloud, you can back up via a Wi-Fi network to your iCloud storage.
You get 5GB of storage (not including iTunes-bought music, iTunes Match and Photo Stream content, video, apps, and e-books) for free or you can pay for increased storage (10GB for $20 per year, 20GB for $40 per year, or 50GB for $100 per year).
To perform a backup to iCloud, first set up an iCloud account and then tap Settings on the Home Screen.
Tap iCloud and then tap Storage & Backup.
In the pane that appears tap the iCloud Backup On/Off switch to enable automatic backups. To perform a manual backup, tap Back Up Now.
A progress bar shows how your backup is moving along.