Most Italian hostels are really just like small guesthouses. A lot of them will have many rooms located on individual floors in a variety of properties. It's rare to find a hostel that occupies an entire building, and you may even find two hostels located on different floors of the same building.
They're independently owned family run operations. Because of this it's important give accurate arrival times when booking as most of them won't have reception areas so the owner himself will probably have to wait to meet you upon arrival.
Italian hostels are some of the most interesting and varied in the world. They're everything from romantic Renaissance villas to fantastic fortresses and old castles, from enchanting ancient buildings to ultra-modern buildings establishments.