“You never get a second opportunity to make a good first impression. –Mark Twain.
Most publishing houses and agents want to receive a book proposal rather than an entire manuscript. A few publishers prefer only a query letter. An editor or agent spends an average of twenty minutes reviewing your book proposal, so it is imperative that you provide the correct material and that your manuscript looks professional. To determine the submission format for each publishing house, check the Christian Writer’s Market Guide or check each publisher’s writers’ guidelines online.
There are many different ways to do a book proposal. I am giving you the simplest form. If this is your first book, you want editors to read an actual chapter in the 20 minutes they will allow you. I would suggest trying to keep your proposal under 40 pages.
If an editor or agent requests a manuscript from you, then in that case, follow those specific guidelines. For example, New Hope Publishers, which my recent books are with, wants a very detailed proposal. Our first one was 54 pages, but keep in mind this was requested material.