If you haven't gotten this information yet, let me see if I can help you. Besides, I've written a couple and I'm currently working on another but it takes a little patience.
A Query Letter is nothing but a single page cover letter on introducing you and your book. It consist of 3 paragraphs, the hook, the synopsis and the writer's biography.
A hook is a one-sentence tagline of your book - it's meant to hook the readers interest and entice them, the agent, publisher, and etc., to ask for more.
The synopsis is where you get to distill your entire book or summarize your entire book into one paragraph. This where you get the tell the juicy stuff, the problems, the conflicts of your book and etc., - which can be worst than pulling teeth!
Then there is biography which is the easy part, this is about you, the writer those special things such as writing schools, awards and accomplishments etc., but keep it short.
Then your closing statement - a formal closure and that's it.