Techniques of the Selling Writer by Dwight V. Swain
The Writer's Journey - 2nd Edition - Mythic Structure for Writers by Christopher Vogler
When I decided to write a book, I just sat down and did it. There's a story in it somewhere, but the POV is all over the place, the plot meanders and the characters are all ineffectual. It's bad.
By the time I conceived the idea for my next book, I was involved with the Virginia Romance Writers and started attending meetings and workshops. Whoa, was there a lot I didn't know!
Some fiction writers are born with an innate ability to craft a story. The rest of us need some help honing our craft and discovering what our process will be. I started out as a "by the seat of my pants" writer, but then found I worked better by starting with an outline.
Whether you're one or the other, I still highly recommend the books listed above. They've all been around forever, but the basics don't change, and each of these books in its own way reveals the secrets of telling a successful story.
Marketing your books is a different subject, but do start with writing a good book.
I even found that these books made me a better reader AND a better movie-watcher.