The book "Real-world Decision Modeling with DMN" by James Tylor and Jan Purchase was released in time for th eend of the year (ISBN 978-0929652597, Amzon.com-Link).
I had the honor and the joy to review the book upfront and to give some feedback in the finalization. For sure you need to explain the notation in such a book. This alone would be a bit boring. Starting to use a notation we see the same questions again and again: How to scope? How to structure? What additional information do we need? You need working techniques, method and the context. These questions are for an successfull use of the notation really important. Insteat to go for a "Certification" for a notation user should seek answers for these questions.
The book offers a lot of "brainfood" and shows the big experience of James and Jan. It is a breath of fresh air compared to other books (e.g. The DMN Method and Style by Bruce Silver). The book has a lot of examples. Many of them from the Finance Industry. This is caused by banks and insurances adopted "Business Decision Management" early. The examples can easily be applied to other industries.
The described working techniques are no dogma. Some are of general nature (e.g. How to scope?), others depend on the situation. Everybody has to be creative and critical. What is good for my initiative and use case? This requires experience.
I hope the book reaches many readers.