Proposals are for non-fiction and are generally not done for fiction as fiction agents/publishers expect to see a finished product before they will consider the work anyway. Non-fiction is sometimes considered on spec(through the proposal process).
The exception would be a successful fiction author who proposes their next book to a publisher before writing it, but I expect that would be a less formal process than the non-fiction book proposal process.
So, you won't find books on developing fiction proposals. Once the work is finished, you simply perfect your synopsis and query and start sending it out. It makes the synopsis and query much more critical in the fiction writing business, because that's the only way we get published through traditional means.
As for self-publishing, if you choose to go that route, you may want to consider paying a professional editor or hiring editing services to give your first few chapters or your entire book a good once over. You'll pay anywhere between $500 and $1500 for reputable editing services (depending on the length of your book and the service you choose, but it will be worth it if you're self-publishing.
The Department of Continuing Studies at the University of Wisconsin, Madison, offers book proposal writing workshops and many more online.
http://continuingstudies.wisc.edu/lsa/online/writing/index.html
They also have editing services available for a fee per page.
http://continuingstudies.wisc.edu/lsa/writing/critique.asp
I'm not affiliated with them, but I have attended their workshops and plan have used their critique services. They do a good job, but you might find something similar closer to home, wherever you are.
Good luck with your projects!
On edit: Look for a writers guild (available by genre or for literary fiction) that you can join. They are great at tracking the good, the bad and the ugly in the editing/publishing world, will keep you on top of the latest scams, and will help direct you toward the kinds of things writers like you need to get published. There is often a fee for membership, but it's worth it. I'm a member of a genre fiction guild that offers a searchable index and up-to-date contact information for agents and publishers for my genre, online writing workshops, a forum for questions just like you're asking here, and the latest news on the publishing world, from scams to court rulings to copyright changes and more. It's more than worth the $100 per year to be a member.
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