A Tageskarte lists the menu of the day. Seasonal menus, or Saisonkarten, feature seasonal dishes, like white asparagus or red cabbage.
In most restaurants it is not customary to wait to be seated. Simply walk in and take any unreserved space.
German restaurants do not automatically serve water. If you order water, you will be served mineral water and be expected to pay for it. The concept of free refills or the bottomless cup of coffee is also completely foreign.
Cash or Credit? While German restaurants will occasionally accept credit cards, most expect you to pay cash (even for large and expensive meals). If you are having something small, like coffee and cake, you will definitely need to pay in cash.
Tipping: When you get the check for something small, like a cup of coffee, round up to the next even euro. For larger amounts, tip 10%. Also, instead of leaving the tip on the table, add it to the total amount when you pay. For example, if the bill is €14, and you want to tip €2, when the waitress comes to collect the bill, tell her the total amount (cost plus tip) you want to pay ("€16, please").
German waitstaff are more than happy to split the check so that everyone can pay individually. Remember to pay the waiter directly; do not place the money on the table and leave.