Five Basic Steps of Running iCloud on your iOS device.

1. Make sure your device is running the latest version of iOS.

If you are setting up a new iOS device, or to update to the latest version of iOS. Go to the
Settings menu-> tap General, and tap Software Update to see if there's an update available.

2. Turn on iCloud.

When you turn on a new iOS device or after you've completed the update to the latest version of iOS, follow the instructions in the setup assistant to activate your device and set up iCloud.

If you skipped the setup process, tap the Settings icon on the Home screen, select iCloud, then enter your Apple ID.

3. Customize your settings.

Tap the Settings icon and select iCloud. Tap the On/Off switches to enable individual iCloud services. To enable iCloud Backup, tap Storage & Backup and turn on iCloud Backup.

4. Enable automatic downloads in Store settings.

To enable automatic downloads for your music, apps, and books, tap the Settings icon on the Home screen and select Store.

5.Turn on iCloud for the rest of your devices.

To get the most out of iCloud, set it up everywhere.

Feature:
Free iCloud email account.

With iCloud, you can get an iCloud.com email account that's ad-free, is up to date everywhere you check it, and includes webmail at Cloud.com. Just turn on Mail in iCloud settings and follow the onscreen instructions.
Reference- apple.com