We’ve discussed a book (or series of books) in the past, but we have no concrete plans to produce one. Printed books for something like Unreal Engine - which changes all the time and has a short development cycle between versions - are not the best investment in terms of resources. We would much rather focus on documenting the aspects of the engine that we haven’t gotten to spend much time on yet, and improve the usability of the existing resources as well as investigate new ways of presenting information both inside and outside the editor. I feel like that is a much better way to spend the limited resources we have on the documentation and learning resources side of things.
there are quite a few threads on the forums where I have posted about this in the past which may be of interest to you. We are always interested in hearing people’s thoughts.
Let’s not hijack this thread with that discussion though. 