I regularly coach people who are in various phases of intention for producing their first book. It's gratifying to see people realize dreams of bringing often important bodies of work to their targeted markets. The only way to learn this craft is good mentoring, reading and practice.
I always support those blogging and thinking about blogging. Even irregular blogging can be an ideal platform for inspiring research, playing with language and getting valuable feedback. Even if you don't do a book, you still contribute great value to your world, become a better writer, and create content that, who knows, could one day support a new book project.