To query or not to query, that is the question...

Having received my first rejection, I have some decisions to make. The first decision, to revise my query letter, is an easy one - it obviously needs to be revised. The second decision, who to query (agent(s)), is not an easy one. I'll deal with each issue separately.

Query revision:
I have read multiple books and websites and they all give different guidelines regarding the number of paragraphs and what to say in your query letter. Most agree that a query should be one page. Some say to use a standard three paragraph query, while others give examples of winning queries that were longer than, and more detailed than, the standard three paragraph query. Confusion abounds here. I recently read a query letter in the 2010 edition of Writer's Market - their example of a good query letter was one page, but consisted of eight paragraphs. So my trying to force everything I had to say into three paragraphs could have been my undoing (may have led to my first rejection).

Query to agents:
Some agents require exclusive submission while others state that they accept simultaneous submissions. Much as I would like to increase the statistical likelihood that an agent might want to see my entire manuscript by sending out multiple submissions, I must say I'm a one agent/one relationship-type. Which leads back to the first question: with each rejection, do you continue to revise your query letter?

UPDATE: Just created a submission tracker in excel so that I can keep track of submissions, rejections, and form rejection vs. rejection with comments.