Again, you will find a lot of information in the three languages (English, French, German) and some forms for the registration for the event and the accomodation. To use one of this forms you need a valid account at the DmD website.
As usual, you have to register first for the DmD event and will get the secrets to use the forms for the accomodations.
For the campsite you have to use the forms on the website of the campsite.