I tried to search old threads for this, but so many results came up that didn't answer my question, I figured it might be easier to start a new thread... I apologize if this has been answered before!

I recently submitted a full ms to an agent, and she sent me a follow up email today saying she's about halfway through it, but she would like a full synopsis of the novel. I've never written a synopsis for fiction (only just the two-paragraph blurb that might go on the back of a book) and I obviously don't want to do it wrong since it's for an agent.

Is there a format? Any pointers anyone could give me? Do you give the ending away in a synopsis? I can pop out fiction at a dizzying pace, but when it comes to writing things like summaries or query letters and the like, I'm really awful....