The two main platforms where your book can be accessed by those you are wishing to reach are the eBook and Audio book platforms.  There are many websites and Youtube videos that will guide you through the process of  publishing eBooks and Audio books.  I found Rich Blazevich Youtube channel very helpful in guiding me through the process of eBook publishing.  A good place to start in publishing an Audio book is Findaway.  This is the website I have used to distribute my audio book.  There are many other website and Youtube videos that will guide you through the process of publishing. 

Who am I writing this book for? Having a crystal clear answer to this question is essential if your book is to reach those you are wishing to serve.  Once you know who you are writing for you can then prayerfully begin to promote your book.  A promotion plan can include a distribution list, advertising, social media, pod cast, promoting in churches, book launch, and the like.   The goal of promoting your book is to reach those to whom your book is seeking to serve, not getting it out to as many people as possible.