Sometimes writing a query to an editor or agent is harder than writing the actual story. At least, that’s the way it seems to me sometimes. Getting everything you want to say about your pitch on one page is challenging. How do you grab an editor’s or agent’s attention? What do you say to make that editor or agent want to see the entire manuscript? Not easy.
A while back, I read How to Write Irresistible Query Letters by Lisa Collier Cool. Good book. It’s been updated since then. My copy is an older version, but I still found it very helpful. There’s a sample of a successful query and the agent’s reply on this link from a Writer’s Digest blogger (Chuck Sambuchino). Check it out. Great luck on your queries!
"The nonfiction query letter serves two purposes: It should convince the editor that your idea is a good one for her readership, and it should sell you as the best writer to cover the topic." -- Writing tip from Writer's Digest Weekly Planner