What kind of herbs are common in Italian dishes?
Some example of herbs usage here in Italy (I'm 100% italian living near Milan):

Basil: (for its fresh taste)


Pasta with tomato sauce and a couple of leaves of fresh basil on top.
Pizza Margherita: Mozzarella Cheese, tomatoes, basil. 
Pesto: basil, parmigiano cheese, pine nuts &amp; olive oil.


Oregano: (a little salty, chosen for its strong parfume)


On top of Focaccia
Mozzarella Caprese (mozzarella, tomatoes, basil &amp; oregano)


Sage (delicate perfume, used to enhance flavours)


Gnocchi with butter &amp; sage, with little parmigiano


Parsley


Mostly used with fish pasta dishes (never with meat!)


Some common mistakes on italian pasta recipes "as seen from abroad" is that we don't really use parsley or oregano everywhere. Many other herbs like tarragon, marjoram, etc... Are rarely used in everyday recipes.