You're written a manuscript, spent hours researching on line, or in the library to be sure you have accurate information before you send it to the editor. Now that the book is finished, and sent away what can you do with all the information that you'e accumulated.
Regardless of what genre you write in if you've done research you should always document it. Do up a list of books, contacts, internet links, etc because if there is a question then you can always go back and say I got this piece of information from this source.
Still it would be nice to do something with the piles of notes and copy that you've managed to create to write a work of fiction. There is a huge market out there for extended essays that are complete nonfiction works. If you're willing to do the extra bit of polishing and work and have a good data system with the links, books etc why not put it all together and submit it?
I know there are publishers out there who take nonfiction and want you to have an agent. That's okay, shop around. Take your time. You've invested time and energy into this project so make sure that it's going to find a good home. Consider the dollar last and you'll find yourself happy to have a home to all that information you've put together.
Good luck, and happy researching!