Tourist visa duration for U.S. citizens in Europe

Hey all, with my American passport, do I have 90 days here in Germany and if I want to travel Italy after 89 days here, do I have 90 days there? Or is it 90 days in the Schengen countries? Also, I have been here one year on a visa. When this expires, do I still have 90 days or must I leave???

90 days includes all Schengen countries. Not 90 days per country..
Depends on the type of Visa you have. Contact the place your got it from and ask them.