Time to start writing that query letter methinks: this site called AgentQuery had some interesting suggestions:
Paragraph One—The Hook: A hook is a concise, one-sentence tagline for your book. It’s meant to hook your reader’s interest, and wind them in. The best way to understand how to write a hook is to read the loglines of the titles sold by agents in our free searchable AQ database.
Paragraph Two—Mini-synopsis: This is where you get to distill your entire 300 page novel into one paragraph. Lucky you. We’d like to offer advice on how to do this, but really, it just takes practice, hard work and lots of patience. Then, like we said before, get your friends to read it and if their heads hurt afterwards, go back to the drawing board. We don’t envy you. We really don’t. Summing up your entire book in an intriguing single paragraph is worse than a root canal.
Paragraph Three—Writer’s bio: This should be the easiest part of your query. After all, it’s about you, the writer. Okay, so it’s a bit daunting, especially if you’ve never been published, never won any awards, hold no degrees from MFA writing schools, and possess no credentials to write your book. No problem. The less you have to say, the more space you have for your mini-synopsis. Always a plus.
Your Closing: Congratulations! You’ve finished your query letter. As a formal closing, be sure to do two things. First, thank the agent for her time and consideration. Second, if it’s nonfiction, tell them that you’ve included an outline, table of contents, and sample chapters for their review. If it’s fiction, alert the agent that the full manuscript is available upon request. And in case you still don’t believe us, we want to reiterate: don’t query agents until you’ve finished your full fiction manuscript. Agents will want to read the whole novel before they offer representation to you and your book.