Some books are better in print, others eBook, lots are good in both.
Many novelists are now publishing straight to eBooks. This is a great strategy when you’re starting out because you can get feedback from the market on your work. It requires less time or expense to publish this way. Books formatted as eBooks are on sale quicker than having them printed and through online stores such as Amazon can be made available to a huge international market.
With instructional material, lots of people like to have the book they are studying next to them on their desk or table, as a reference, to make notes in, to highlight for later study. If you know your readers and their habits, you won’t want to omit this from your plan.
If your book is heavily illustrated, like a photography book, or a book on fine art, you’re going to need to the best digital solution such as an app or fixed layout eBook.
The good news is that now the files produced for a print book, if produced properly, can be easily adapted for an ebook, without starting from scratch, and without having to engage an HTML developer to code the files.