Put it all in...

If you want to write a book, put all you got in it. Don't leave anything back.

If you give it all, people will make a pro in what you wrote. With all that you gave in your book, you know enough to be a great trainer in the subject. And you'll get request for one on one people and even group. A book is only the first step.

When you become a reference in what you wrote, you become book that people will recommend to friends.

Yes, some could find your book too filled with stuff and info. And some will not read it at all. But those that do, if they think that you did a great job, they'll bring everyone into thinking that it's a great book.

Giving it all is also a great way to feel good. You know you did the best job you could at that time.