I,too, think there is much to see in Germany, and your time is well spent doing that with a German railpass. As to planning the trip, I can recommend "Gemuelichkeit"'s trip planning and booking service. This is a small specialty travel newsletter for Germany, Austria and Switzerland. They do hotel bookings, restaurant recommendations, backroad itineraries, and self guided rail tours. They can be reached at 800-521-6722. (I am not affiliated with nor have any involvement with this company) Most important is to recognize the wide variety of sights and experiences available in Germany, from the rural and scenic mountain country in Bavaria, to the museums, beer and laid-back urban life of Munich, to the sophisticated, ultra-new excitement of Berlin ( it may be the liveliest capital in Europe), to the North Sea or Baltic Sea coast, the Rhein and its vineyards and castles, the glorious wine country of the Moselle River..... well, you get the idea.

You can, if you wish, stay in a thousand year old castle, and sit on its terrace sipping a glass of Rhein wine while watching the river traffic below on the Rhein. Or you can stay out all night in Berlin and wonder at how quickly the night went. Stay long enough to truly experience Germany and you will not regret it.