Over at Chuck Sambuchino's Guide to Literary Agents' blog, he includes advice from Janet Reid regarding what to include and what to cut from your query letter. It's definitely worth a read. Check it out here.
While you're at it, Cynthia Leitch Smith has posted some great agent interviews on her blog Cynsations. (Agents Sarah Davies and Laura Rennert among others).
An Interview with Jessica Faust
16 hours ago