1. Create an Outline from What You’ve Written
Your first step is to read through your book, and create an outline from what you’ve actually written. Create the outline in another document, and print it out.
If you see gaps in the structure where you need material, mark these areas on the draft.
You've written a first draft of your book. What comes next? Editing comes next -- it's the difference between a book which may sell, and a book which WILL sell. Yes, you can hire an editor, but you need to do the basic edits yourself. It's YOUR book, after all, and you know what you want to achieve.
Let's look at a simple editing process -- you'll find that editing is lots of fun. I always enjoy editing, because I know that the book is written.