I´m actually looking for some book about Irrlicht and/or 3D-Engines in general. What I want to get out of that book is to be able to use and understand the irrlicht-engine. I guess there are many things quiet similar in the engines available, so maybe there is a good book which is not specific to the Irrlich engine.
I'm not sure the book you linked will be the most help to you. Have you tried looking at the tutorials in the SDK? They do wonders to explain how Irrlicht works.
There's really no book on Irrlicht. I'm sure you can find dozens of books about 3d rendering in DirectX and OpenGL, but I'm not sure how much those will help you either since the whole point of a graphics engine is to abstract those two to make things simpler.
No, but if you tell us what you'd like to do, I'm sure myself and the rest of the Irrlicht community would love to help you out with whatever you have in mind.