Apple’s latest iOS update will be online within the next 24 hours, and you’ll want to get your hands on those new features as quickly as possible.
But before you do, you should back up your device. Backing up is basically making a mirror image of your iPhone or iPod Touch as it exists right now, complete with apps and settings. If something goes wrong during the upgrade, you can always restore from backup, and your phone will appear as it did before.
To backup, just plug your phone into iTunes and select backup from the summary screen. You can also make sure you backup to iCloud through that screen, or through the settings feature on your iPhone through Settings, iCloud, and then “Backup and Storage”. Select “iCloud Backup” to on, and away you go.
If you want to be really sure you have a backup handy, make sure you backup to both the iCloud, and your computer.