First, you’ll need to back up all of your data and settings.  Doing so will allow you to effortlessly transfer all of your apps, music, contacts, photos and more over to your new device.  One of the quickest ways of accomplishing this is through the use of iCloud.  If your device is running on iOS 5 go to: Settings > iCloud > Storage & Backup > Back Up Now.  iCloud will back up all of your app data, Camera Roll, settings, iMessages and ringtones, as well as keep a record of all of your iTunes, App Store and iBooks purchases so you can restore them later.  However, iCloud will not back up music or videos you’ve copied from disks.

If your device is running iOS 4 or later, you will have to back it up using iTunes.  Simply plug your device into your computer and iTunes will automatically sync and back up your content.

After you’ve backed up your data, the next step is to securely remove all of your personal information.  The simplest method of clearing out your device is by going to: Settings > General > Reset > Erase All Content and Settings.  This may take some time depending on how much data you have on your device, so make sure that the battery is fully charged, or plug it in before deleting.  When the resetting process is complete you will see a prompt on the screen asking you to connect your device to iTunes.  Do not connect your device to iTunes.  All this prompt means is that your device has been successfully cleared out and restored to its factory settings.