The Contents of the Proposal
Although some genres have specific requirements and some editors and agents prefer a certain format, a standard table of contents will consist of the following sections:
Overview
Target market
Promotional plan and platform
Author's vita and bibliography
Competitive books
Chapter-by-chapter outline
In addition to the sections that comprise the table of contents, two sample chapters should be included in the submission. These chapters need not be consecutive nor need they be the first chapters of your book.
The Overview
In many ways, the overview is an extension of the query and consists of approximately ten pages. The overview must hook the reader in the first paragraph and provide a “selling handle” that pitches and succinctly states in a sentence or two what the book is about — something that could become the subtitle on the front cover.
How long should my book proposal be?
A typical book proposal ranges between thirty to forty pages. This is exclusive of the sample chapters. Some agents and editors have specific requirements as to format and length that you might want to review before submitting.
The overview expands upon the other issues touched upon in the query:
A summary of the book
Why the book is important and should be published
Why the book will attract readers
Why you are the one to write the book
The length of the book and time needed to complete it
Author's Vita and Bibliography
This section of the proposal should be presented as you would any professional resume or vita. It can list all the relevant information or provide a narrative written in the first or third person. In the overview you have already addressed why you're the one to write the book and later in the promotional portion you'll explain what you intend to do to help sell the book. Consequently, all you have to do in this segment is provide basic information about yourself.
Be certain to include anything that qualifies you to write the book and your experience as a writer. If you have previously published, you should add a “bibliography” or a “list of publications.” If you have only several credits, you should incorporate them into your vita.
The chapter-by-chapter outline is not an “outline” in the strict sense of the word. It should be written as a narrative in the same style as the tone of your book. While summarizing the information, it should demonstrate how the book will actually read in addition to the sample chapters provided.
Outline
This section of the proposal should be about ten pages and summarize your book chapter by chapter. Obviously in order to write this, you will have thought out the book from beginning to end, which is exactly what an agent or editor is looking for. The form of the outline is chapter by chapter with one to three paragraphs describing each chapter's contents.
Sample Chapters
Although part of the book proposal, the sample chapters stand by themselves and should be page numbered separately. You were informed that the chapters need not be from the beginning of the book nor consecutive and in fact, it is wise to provide chapters that offer different perspectives of the book. Should you have an introduction to your book, you can include that as a sample chapter if it is the approximate length of your chapters. And speaking of length, two sample chapters will generally suffice unless they are short (less than ten pages), in which case you should submit three chapters.

