A book proposal is your calling card to literary agents and publishers. Despite a few exceptions, such as novels or memoirs, most authors write a proposal to sell a book and get an advance payment for it before drafting a manuscript.

Here are five good reasons why you, an aspiring author, need to draft a book proposal:

1. To persuade an editor and publisher to acquire your project. If they don't see your ideas spelled out on the page, they won't be as willing to take a risk. The proposal gives them an opportunity to point out flaws in your material and make changes.

2. So you know what to do when you're writing your book. A proposal serves as the blueprint for the book you plan to write'all you have to do is follow it. This map helps you build a book with a solid structure that will stand the test of time.

3. To educate your publisher's production and design team about the book's appearance. A cookbook must look different than a biography or diet book, for example. The book proposal gives your publisher's graphic artists sufficient material to inspire them to create an appropriate interior and cover design.

4. To inform your publisher's publicity, sales, and marketing team about your personal and professional contacts and activities, and potential niche marketing opportunities, so that they can strategize how best to promote and sell your book.

5. To outline a business plan for your career. As a general rule of thumb, from conception through promotion a book is a three-year project. In order for your book to be financially successful, promoting your book is essential.

In my publishing course Writing Your Breakthrough Nonfiction Book Proposal, I always tell students, 'Publishers are looking for fresh ideas and want to work with authors who will make their lives easier. If you show the publisher that you understand your market, where your book fits into it, and why you're enthusiastic about your subject matter, you'll generate interest and attract the right publisher'an appropriate fit for your business. They want to read good writing and know how you plan to promote your book.'