The good news is that all of your primary track information should actually be stored in your media files themselves, and i Tunes will pick this up when you reimport those files into a new library.The only information that will not come across when importing tracks into a new library is i Tunes-specific data such as ratings, last played dates, play counts and your individual playlists.So with all of the above in mind, your best option is to choose whatever library you consider to be your “primary”—likely the one you load your i Pod and i Phone from—and then ensure that you’ve consolidated all of your content from that library onto the networked hard drive by following the instructions in our tutorial on Transferring your i Tunes Library.
This means that you will essentially need to manually import all of your music and other media files into a single library database.
This can either be a completely new i Tunes library that you create in order to consolidate everything, or you can simply import the content from your other libraries into whichever is your “main” library.
However there are Applescripts that can be used to manually adjust information such play counts and last played dates and it is possible to export your playlists from one library and import them into another.
You can also easily keep your media content on the networked hard drive, although you’ll want to be careful about setting up more than one i Tunes library against that networked location as you’ll only be sharing your —the individual library databases won’t be automatically kept up to date and it will therefore be easy for things to fall out of sync with each other.
Home Sharing does not transfer star ratings or play counts for music.