Jill Corcoran is a writer agent who has a very informative blog. Here is her page on How to Write a Query Letter.
I don't know about you, but that's one of the hardest thing there is for me to do. I usually blather on and on and forget stuff and . . . well, you know. She includes useful links and advice and I thought I'd share it with you.
As to submitting, she is one who doesn't answer if she doesn't want you. Usually I am against submitting to someone who does that. However. Her time limit is one month. Not ten. I can live with that so I probably will submit to her.