The tour usually covers around 28-30 kilometers and is accompanied by the police who block off the street while the skaters come through.
1. You need to be a really good skater, especially when it comes to braking
2. Helmets and other protective gear are highly recommended
3. Reflective clothing is also recommended
4. Stay to the right, pass on the left
5. Skating on the sidewalks is forbidden!
6. If an accident occurs, either keep on skating, or help out, don't stop and gawk, blocking the way for emergency vehicles, etc.
7. Volunteer helpers should be listened to, they help with the organizations, accidents, etc.
The website has a map of the meeting point as well as lots of cool photos. We love watching them skate past our house. I often think it is raining, but it is just the sound of 100's of wheels. There are always skaters carrying boom boxes, so the atmosphere is one of a giant rolling party. Parents have their little ones in jogging strollers, so it becomes a bit of a family affair.
Many cities do this, so if you are a skater, you might want to think about bringing your skates with you when you travel to Germany and check out the individual city websites to see if they have this activity.