Q: My wife and I have separtate iPods and separate computers. I have built a substantial library on my computer, and she wants to transfer my iTunes library from my computer without losing the songs that she already has on her own iPod, and then be able to pick and choose what songs she retains via her own computer. What is the best way to accomplish this?
– Chris

A: There are a couple of different ways this can be accomplished, and the simplest way might simply be to copy your music files to your wife’s computer using an external hard drive or network connection. If she simply imports your music files into her library, then she can sort through them in her own iTunes library and sync the ones that she wants to her iPod from there.
Note that if you have sufficient free space on the iPod itself, you can even use this as your external hard drive to transfer the tracks into your wife’s iTunes library. To do this, simply select the Enable Disk Use option for her iPod via the iTunes “Summary” tab:
This will cause the iPod to be accessible via Windows Explorer or Finder as an external hard drive, and this setting will actually travel with the iPod between both of your computers. You can then simply connect her iPod to your computer and copy your music files to it as if it were just another hard drive (it should appear as a drive in Windows Explorer or Finder). She can then connect that iPod to her computer, and simply copy the files from it via Windows Explorer or Finder, and import them into her iTunes library as she would any other track.
Alternatively, if she plans to regularly transfer music from both your computer and her own, you may want to simply set her iPod to “manual mode” as per the instructions in the previous question. This will allow you to drag-and-drop music from either iTunes library onto her iPod. Unfortunately, with the exception of iTunes Store purchased music, there is no built-in way to transfer these tracks back to her iTunes library. To transfer the music from the iPod back to her computer if it has been loaded on via iTunes, you will want to consider some of the options discussed in our tutorial, Copying Content from your iPod to your Computer.