My sis (23), and I are travelling to Germany for two weeks. It seems like we have read every guide book but cannot finalize an itinerary. In addition to some of the major cities, we'd like to see the country side. We've been told to rent a car for a week but where do we start and end? Love to see wine country, the alps and do a bit of hiking. On the other side, it's suggested to use trains and they also mentioned fahrplanauskunft db but we are confused. What you guys recommend?

Any help would be appreciated. Thanks!