This section is also sometimes called “Chapter by chapter outline.”
Write a few sentences or a short paragraph on each one of your chapters. Give the editor or agent a good, solid idea of what you will cover and include in each chapter.
Of course this also means you are giving chapter titles, will know how many chapters will be in your book, and what will be in each one of them.
By the time you’re able to write your sample chapters and chapter summaries, you’ll need to have a really good handle on your book. You’ve already done a good portion of your research. You’ve organized your material. You’ve mapped out how you’re going to move through your information. You not only know where you’ll start your book and end it, you also know where you’ll start and end each chapter.
In other words, by the time you get here you’re probably more than half-way through writing your book! Isn’t that cool?
Still, you have wiggle room. While you’re asked to map out your whole book, the map you create isn’t set in stone. You are creating a book proposal. You’re giving them a solid idea of what you plan to do, however if you get a better idea or if they want to adjust something, you can still do that. So don’t get too antsy about making decisions and planning your book. Editors and agents understand that this is just a proposal and (probably minor) things can change when you write it.
FICTION WRITERS: You don’t need to divide your story into chapters at this point. Instead of a chapter by chapter summary, just write a synopsis of your story straight through with no chapter breaks. (And yes, you are supposed to tell the ending. I know. It’s a spoiler. But your prospective agent and/or editor needs to know you can finish the story.)