Welcome to the Apple Support Communities. If iTunes does not see your mobile device, check out the following that goes over the basics.
With the new version of iTunes, it would be the the left of the iTunes Store icon
If you like how itunes worked before, I will suggest taking a look at the article that will bring back most commonly used features in iTunes.
In iTunes 11 you have the option to turn the Sidebar and the Status Bar on or off; they are off by default. To do this in the menus, go to:
- Show Sidebar - Choose View > Show Sidebar (this feature will display iTunes features on the left side of the application including Library, Store, Shared, Genius, and Playlists).
- Show Status Bar - Choose View > Show Status Bar (this feature will conveniently display the number of items and playback time for a category, for example, music or movies).
If it still does not show up, then the next best thing would be schedule a Genius Bar Appointment.
Have a good one.