I am writing a book this year on the ElephantPM project management system and I am presently trying to decide whether it should be available as an eBook. This is an informative article,
Will Gutenberg laugh last?
It has been taken on faith by many, including your benighted scribe, that the future of book publishing is digital, that the e-book will displace the printed codex
Dr James Bayley 
Good luck with finishing the book James. I look forwards to reading it. Personally I prefer text books in print form so that I can stick post-it notes all over them and write on the diagrams, which I still don’t think can be done satisfactorily in e-books. I think Gutenburg can keep chuckling for a while.
I am writing a book on ElephantPM. My research has convinced me that this should primarily be a paper book. Probably in landscape format so that people don’t put it on bookshelves but leave it on their desk for immediate reference.