Hello! My name is Humberto Valle, I'm the co-founder of www.Unthink.me, growth hacking and digital marketing service. I can go over all the different tactics and strategies that you can implement but there is a book by a fellow growth hack marketer, Ryan Holiday, in this book he talks about how he did just what you are looking for.
In essence, he scheduled his book release with enough time that allowed him to promote snippets of the book through blogs, forums, influencers, etc and get traction on this website to capture emails from interested marketers and business owners. You can also trade emails for snippets/sections of your book as well as schedule a timeline releasing chapter by chapter through a blog wrapping up the entire project with the release of the book itself. (sounds contradictory, but if your book is good people will want to have a physical copy and support you for it)
Once the book is launched you reach out to influencers who have shown support before hand as well as through emails and even paid ads. Check out his book is definitely worth it.