If you have multiple iPods or iPhones in your household and wish to have each device synced with its own iTunes library, here is an easy way to create a second iTunes library on the same computer.
Open iTunes on your computer while holding down the "Shift" key.
Select "Create Library" from the pop-up menu box that appears.
Create a name for the new library and click "Save." iTunes will open the newly created library.
You can backup all your audio and video content on your iPod or iOS device straight to your iTunes library using TouchCopy. Simply click on "Backup All " in TouchCopy and then select to "Backup content into iTunes". The backup option in TouchCopy will save your Music, Video, TV Shows, Podcasts and Playlists. Visit the TouchCopy user guide for more details on how to Backup all songs and video from iPod and iPhone to iTunes.
You can also choose to copy groups of iPod songs or playlists to iTunes by clicking the "Copy to iTunes " in TouchCopy, as detailed in the TouchCopy User Guide.