A useful proposal describes the reader, the need the book addresses and the experience it offers. Include a concise overview, a chapter outline, sample material and a short author biography that explains relevant experience. Keep claims specific and support them with research rather than broad market promises.
Requirements differ between traditional publishers and self-publishing service providers, so confirm what is needed before preparing a package. Even when a proposal is not formally requested, the process can clarify the manuscript’s direction and provide strong source material for a book description and marketing plan.