Highly valuable tips & tricks, all of them encouraging, which is rare. Usually authors start with 'Don't write a book' or 'Think twice before start writing a book'.

I've also started writing a technical book and I find it challenging in the same pleasant way.

Writing is much much harder than programming because you can't test prose and you don't have a programming language. But the deliverables are the same: something which runs flawlessly on a processor.

Writing a book is much harder than writing articles because a book has to stay interesting for hours, while an article for just a couple of minutes.

Getting a writing mindset is far harder than getting a programming mindset: I can write code any day, any time but sometimes I can't write a paragraph a day.