Create the habit. Good or bad, habits always deliver results. If you only write one page a day, in a year, you will have written 365 pages—more than enough for a book!
Find your message. There is a book inside of you. It might be a business book, a memoir, a cookbook or something funny, a how-to or how-not to, a what-for or why-not. What are you good at? What is your passion? What can you teach other people to do?
Knowing your niche will help you write the book and market it.
source: Jack Canfield