Apple has had some iTunes tutorials on its website for a while, but iTunes 12 is bringing these tutorials front and center. It seems that the second time you launch iTunes 12, a window displays showing the iTunes Quick Tour.
This window cycles through a number of pages, telling you how to navigate the iTunes interface, how to use the iTunes Store, how to listen to iTunes Radio and more. It’s a cursory introduction, but may help users who are a bit flummoxed by the new iTunes interface. Of course, it might have been better to display this when iTunes 12 was first released, instead of waiting for an update.
If you ever want to see this window again, choose Help > iTunes Quick Tour.