I want to make your Book Proposal shine! A book proposal should only be sent to an agent or publisher after he or she has asked for one, following your Cover Letter and Synopsis. If you are asked to send a Proposal after they have read those two "sales pieces" you can consider yourself as having started a relationship. The Book Proposal is a very different animal. It contains five essential (and separate) parts and needs to be written in a specific order. Once this is accepted, you may just be on your way to a book deal.
If I have read the book I will be able to write the proposal without notes, but if I have not, I will need a complete description of the plot and characters and what you want emphasized in the proposal. It is not a good idea to have anyone who has not read the book write a proposal to an agent or publisher, but I can do it with a lot of instructions if you absolutely cannot pay me to edit first. (I understand limited budgets well, but I do advise if you choose this method, at least write an initial first draft so I can see your plot and what you are trying to accomplish with the book through your eyes.)
Please remember another thing: some bestselling authors admit they have sent their Cover Letters, Synopsis, and Proposals to as many as fifty agents and publishers. If you are not into longterm, there are many ways to self publish WITHOUT COST. NEVER PAY A VANITY PUBLISHER. Amazon Kdp and Smashwords (eBooks) and its (print) partner, Draft2 Digital are both good options for self-publishing.