This four-week course, N130 The Non-Fiction Query Letter & Book Proposal, will show you how to write an effective query letter for your non-fiction book proposal. To query or not to query, isn't the question; however, to query the right agent/editor and get the request for your non-fiction proposal is. It is suggested you look for the publisher or agent guidelines before querying. With a non-fiction book proposal, most publishers will only accept agented submissions. Check before sending the proposal along with your query letter.