We don’t often do this, but rather than recapitulate what another source has, we’re simply going to note that the Los Angeles Times has an interesting article on how to take a good idea and turn it into a book which then sells movie rights for a lot of money. Then, on the strength of that option, sell the book manuscript for a huge sum, and write three very successful sequels, all while watching the movie not get made by several production studios.
The book is Meg, the author is Steve Alten, and the article is here.