Stick to the relevant speed limits, however frustrating it may be. It may be hard for tourists to stick to a (sometimes) suburban speed limit of 30 kph, but rest assured, if you get caught, you will get hammered. Also, if you are visiting in a car, make sure that you have headlamp converters fitted (for english vehicles), as well as a fire extinguisher, a warning triangle, fluorescent waistcoats/jackets for both the driver and all passengers, and a first-aid kit. Failure to have any of those will result in a hefty fine, so be warned. Also, many minor roads operate on the "priority to the right" system, so if there are no road markings, beware of cars joining from the right. They may have priority.
In Goettingen, there are probably 10 bikes upon 1 car, so it's a very tempting place for bike thieves.... sometimes your bike may be also "used" by a drunk student heading home from the bar. Many people in Göttingen have 2 bikes: One shabby one for going to university and into town and one good one for bike tours etc.
Lock your bike well!!
Motorists need to be very cautious on Göttingen streets as cyclists rule the streets -- at least they behave this way!