Perhaps it might be wise to first read up about the German railway system. I'll update this page as soon as I can. For the last couple of years the German Rail have been implementing a new philosophy in train travel. One very obvious sign of its modernization are the new cars, which have defined new colors outside and better seats inside. It is a good idea to use these if possible.
Foreign cars are also nice.
There are also first class cars in most trains. You don't really need reservation in most trains. There is no reservation possible for any short-distance trains. The German high speed train. Ticket prices depend on ICE speed and the speed of other trains at the same distance.