If there are more than one iPod in your family, for example, you have an iPod Mini and like classic music, your son have an iPod Shuffle and like pop music, you can make two iTunes library on your computer, one for you and another on for your son. For create secondary iTunes library, please follow below steps:
Step 1. If iTunes is running, exit it.
Step 2. Hold down the Shift key then click iTunes’s icon to start it, until this dialog appears:
Step3. Now you can release the Shift button. Click Create Library button in the popup dialog, and enter a library name, like iTunes 1, then press OK button.
Now iTunes will open with a brand new library, you can add music, video and apps to the library and sync to iPod.
To switch between multiple iTunes library, just hold down Shift key when start iTunes, then click Choose Library button from popup dialog.
From iPod to Computer Transfer v 4.8, it support multiple iTunes library, just swith to the right Library with iTunes before your transfer music from iPod to iTunes.