The Cover Letter
Whether you're sending an unsolicited proposal or responding to a request for material, your proposal package should include a cover letter. This letter should never be longer than one page. Its sole purpose is to introduce you and your work to the agent or editor, or, if the agent or editor has asked for your proposal, to remind him that he asked to see your material.
If the agent or editor asked for your proposal in response to a query, you might include a copy of your original query in your proposal package. This helps remind the agent or editor why her interest in your project was piqued, and it saves her the trouble of searching through her files to find your original query. However, don't let a copy of your query act as a substitute; you still need a separate cover letter.
At many publishing houses, one editor may be in charge of more than one line or series of fiction. If you're sending a book proposal with a specific line or series in mind, make sure you specify this in your cover letter. Otherwise, you might end up with an undeserved rejection.
Your cover letter should include the following:
Your contact information, including telephone number with area code and e-mail address
The genre and target audience for your novel
The word count of your entire manuscript
A very brief description of your story, no more than two paragraphs
A thank you and call to action in the closing
As always, make sure you have the correct name and title of the person you're sending the proposal to, and keep the tone of your cover letter professional and businesslike. Also check the mailing address for the agent or editor. Large firms often have more than one office; make sure the person you're sending your proposal to works in the office you're addressing it to.
Don't tell a prospective agent or editor that “everyone” will want to read your book. If you're writing for a specific type of reader, identify the reader's key characteristics — whether the audience is likely to be women, Latinos and Hispanics, and so on. If you can't narrow your target audience, simply state that your novel is intended for a general audience.
Markets and Competition
Unlike the nonfiction proposal, you don't have to include separate discussions of your potential readership or competing books in your fiction proposal. However, your cover letter should indicate the genre or category of your novel; you can even say your novel is “similar to” the works of Dick Francis or “along the lines” of Toni Morrison's novels. This helps the agent or editor see where your book would fit on a bookstore shelf. If your novel defies conventional categorization, try to identify a similar quirky novel the agent or editor might be familiar with.