Photos

If you delete photo stream photos, they are also deleted from iCloud. Camera roll photos are only included in your backup, but if you delete them and continue backing up the backup containing the deleted photos will be overwritten by a backup that doesn't, and they will be lost.

To keep your camera roll photos, import them to your computer using your usb cable, as explained here: http://support.apple.com/kb/HT4083. If you need to back up photo stream photos that aren't in your camera roll, save them to the camera roll by tapping Edit (Select in iOS 7), tap the photos, tap Share (the share icon in iOS 7), then tap Save to Camera Roll. Then they can be imported to your computer as well.