Q: My friend’s computer is being ordered but they need to upload some music before going out of town—can they connect their iPod to my iTunes and upload and buy their own music of their choice from my library and store?
A: The short answer is yes, although they’ll want to ensure that they create and/or log into their own iTunes Store account before purchasing any music. You can have content from more than one iTunes Store account stored on the same computer and even on a single iPod, so your friend can purchase music and transfer it to their iPod in much the same way as you would.
The best way to handle this is to set the iPod up to be managed manually from iTunes and drag and drop the music onto it from your iTunes library. This ensures that their iPod isn’t automatically associated with your library and they can more easily transfer that music back to their computer once they receive it and get iTunes setup. If they’re dealing exclusively with tracks purchased from the iTunes Store, then iTunes will prompt them to transfer those purchases back to their new computer the first time they connect the iPod to it. If they have other tracks that were loaded from CD or purchased from other sources then they will need to copy those tracks back over manually. Information on how to copy content from an iPod back to a computer can be found in our tutorial on Copying Content from your iPod to your Computer.