There are plenty of books about the process of writing book proposals. And one of the advantages of this one is it gets to the point. There are barely over 100 pages to read, and for a process like this, that is really enough. Writing a book proposal isn't terribly complicated, but the rules you learn are rules you need. It's very possible.
People do it all the time.
The goal here is to increase your chances. A well written book proposal has a better chance of selling an idea than a badly written one. Larsen's book covers such topics as creating chapter outlines, choosing your sample chapters, and finding the publisher or agent best suited to your work. Larsen also includes samples to guide you in your effort. This book doesn't include a revolutionary new method for selling books.