By American standards, shopping hours in Germany are extremely limited. However, you may find that in many smaller towns and outlying areas of big cities, shopkeepers sometimes close their doors one or two hours earlier. In a department store, it's not okay to walk around with your intended purchase. Another thing-forget the cute guy at the checkout who bags your stuff for you at the supermarket. You can buy one, but most Germans bring their own bags or shopping baskets.
Big sales happen at the end of the summer and winter seasons, and bargains abound.
If you are planning a major shopping spree, wait until the end of January or July. Slowly but surely, nonsmoking sections are cropping up in German public places. In Germany, you can't drive a car until you're 18. But public transportation is so extensive that it will take you almost anywhere you want to go. Ask at the transportation office or at the train station for information on special evening rates, youth rates, or Interrail tickets.