The query letter is arguably the most important piece of writing you will ever do. It is the first — often the only representation of your work that a publishing-world professional will see. If it grabs the reader, it might open the door to further consideration. If not, it will go into the “circular file.” Its importance cannot be exaggerated. Therefore, it must be written with great care.
First, a few formatting rules. Like any business letter, this one is single spaced. It must be no longer than one page. And it is written in the first person.
Your first paragraph should be short and succinct. Begin with an attention-grabbing sentence just like you opened your manuscript with a narrative hook. Take another sentence, two at the most, to expand on the opening. Then write a transitional sentence that includes the number of words in the manuscript, its genre, and its title bolded in capital letters.
The next paragraph begins telling an encapsulated version of the book. You introduce your protagonist and whatever circumstances are pivotal to the story. Another paragraph sets up the central conflict. Another summarizes the action that will lead up to the climax and denouement but does not give those away. Use concise narrative, each paragraph containing anywhere from three to six sentences of varying length and complexity.
Your next paragraph tells something about yourself. If you have any writing credits or experience that enhances your credentials, this is the place to list them.
The final paragraph states what is being included with the letter, which will be an SASE (self-addressed stamped envelope) if you are submitting by regular mail along with any other material the agency allows in a submission. If you are submitting to more than one agency, you should acknowledge that fact. Finally, of course, you want to express your gratitude for the reader's consideration.
On first thought, you might throw up your hands and say it is impossible to include all of the above information on one single-spaced sheet of paper. If you are of that mind, you are not alone. The hard reality is that queries are extremely difficult to write. You can help yourself get the hang of it by prowling your local bookstore and reading the blurb written on the inside front jacket of all published books. The meat of your query should mimic those blurbs.
Well-written queries are an art form. As with any art form, there is a learning curve. The more of them you write, the easier the next one will be. Treat them like you do your manuscript. Do a rough draft, put it away for several days, then look at it again. And again. And again. If you know someone who loves to read and will give you an honest opinion, run it by them in the role of consumer. If this were on the front jacket of a book, would they buy it? Polish and polish until you know you have the best letter possible. When that happens, you're ready to move on to your synopsis.