All in all you can say that Americans are more open and frank than Germans. Germans are more formal and many things that Americans do all day are for Germans only possible to do in family life. An example would be the following: If an American enters a store, he/she usually says "How are you (doing) today?". This is polite in America, but would be rude in Germany because you don't know the seller in the store.
This is probably a result of the German language. If you know a person and he/she is a good friend of yours, you can say "you" to her. In any other case, you have to use the politeness form (otherwise you can be sued) that don't exist in English. That's why it is probably hard for you to understand.

I have experienced a very strict opinion about alcohol in the United States. If you know a little bit about Germany, you probably know that our national drink is beer. Almost every town has its own brewery, its own brand of beer. Therefore, the consumption of beer is higher in Germany. But please don't think that the German population consists of a bunch of drunks!

In Germany, you always use silverware to eat. There is only a few exceptions (chicken, bread). And with silverware, I mean it. It is rude to offer somebody a knife that is made out of plastic.
You can say that the Germans don't eat that much meat. The main food Germans eat are potatoes, followed by vegetables like Sauerkraut and cauliflower. "Fast food" doesn't have a high rating in Germany. However, you will find branches of Mac Donald's and Burger King, too. Another, less important point are the refills in the restaurants: In Europe, you have to pay for every refill of your drink. There are no free refills...

In Germany, the thumb is considered to be a finger, too. That's why we count as you can see in the pictures:

"One" in Germany	"Two" in Germany

Americans usually count this way:

"One" in America	"Two" in America

If you would show the American "One" to somebody in Germany, he would think that you tell him to pay attention.