Here's a rough idea for the basic fiction novel query letter. There are several places on the net where you can go to get a complete description and more samples, it just takes some time to do the research.
[my personal details]
Dear [my agent]
[Include a brief paragraph why you chose this particular agent.]
[hook] Gladys always wanted to be loved. Even if it meant killing to get it.
Troy was Atlanta’s favorite son. He becomes the first freshmen in his college class to receive a grant to attend Oxford. He has everything to look forward to; except Gladys who has other ideas for his future.
Without warning, Troy is kidnapped by the one woman he always loathed and despised. But that didn’t bother Gladys because she knows Troy could become her first love if she just had the chance to spend time with him alone.
Gladys will do anything to keep Troy to herself. If it means dying together then she is willing. Troy doesn’t see it her way and tries to convince her of a love that may kill them both.
[title and word count]
Synopsis, sample chapters and complete manuscript are available upon request.
Thank you for your time and consideration,