Queries, anyone?

Before I go any further, let me explain that queries are my least favorite thing next to pitches. I may be nervous during a pitch, but at least I know I can use the remaining minutes to add flesh to the bones of those two sentences. Queries, not so much. I know the first sentence matters but ,while I can always personalize a pitch to an agent I've met, how to handle the cold queries to those I've culled from the Agent Guides?

How much is too much and how little is too little? I already know not to send an e-pitch on Monday or Friday, and aim for between 9AM (my time) and 2PM (my time) during the rest of the week. I can tell them about my story, yes, but then what? I've not been published, although I've done a couple of reviews for a crime fiction magazine. I've taken master classes at comferences with people such as Anne Perry, Nancy Pickard, Lee Child and Libby Fischer Hellmann, but do those count? And I am working on a second book with the same characters as well as a short story or two.

So, what is the answer? What goes in a query? And do I use the Sakey Rule and attach the first page?