Lately there are different stories and confusion around the Transit Visa at Germany.
Visitors traveling via Germany may need an airport transit visa. Following URL list the countries who need to have airport transit visa.
http://www.germany-info.org/relaunch/info/consular_services/visa/countrylist.html
1. If you are Indian citizen and USA Green Card holder you don't need this airport transit visa.
2. If you hold any US non-immigrant visa , you would need a airport transit visa.
You may not need to take the visa in advance, for now the transit visa will be given at German Airport itself without any cost to visitor.
You can also contact nearest German consulate to get answer if you have any question in this regard.
Here is the URL listing German consulate/embassies in USA http://www.germany-info.org/relaunch/info/missions/consulates.html URL for German consulate India: http://www.germanembassy-india.org/en/willkommen/visa/transit.html
