A book proposal should never be more than 20 double-spaced quarto pages. The primary function is as a selling tool. It uses as few words as possible to generate the maximum enthusiasm for your proposed book. It must answer every question an editor may have , so that he has no reason to say “no”.
A proposal is a map. A solid outline will enable you and the publisher to see where you are going. Writing 2 sample chapters will show whether you can and really want to write the book. If you prove that you can research, organize and write non-fiction, you can sell a book with a proposal consisting of an introduction, a chapter-by-chapter outline, and 2 sample chapters.
With fiction it is more difficult. You need an exciting synopsis of not more than 1 page. Another page should be your bio … what work you have had published up to now, and your accreditations if any.
A paragraph should cite what genre it will belong to – e.g. romantic fiction, historical, sci-fi, thriller etc.; who your target audience is and why you think you are the person to write it. You must also state the length (50 – 60,000 words is an acceptable ms.) You must also state how you will help promote it – e.g. lectures, book signings, TV or radio appearances etc.
The cover page must give all your contact details. Finally, you can send 1 or 2 sample chapters so that the publisher can assess your style. Never send a complete ms. – it will simply go in the slush pile. If it interests them, they will ask to see more. If you want your ms. returned, you must send stamps to cover the postage, or if it is overseas, you send International Reply Coupons that you buy at the Post Office.
You can send multiple submissions. Don’t worry – more than 1 publisher will probably not be interested. You can use an agent, but I have only had an agent find me one publisher – the other 13 books I approached publishers directly although my New York publisher often gets me better deals on the contract. Read books like The Artists & Writers’ Year Book (U.K.) or “The Writers’ Market (U.S.A.) to research which publishers are interested in your genre and any specific requirements they have. Then be patient – you rarely get an answer in less than 3 months. Good luck!