Franci, I just wanted to add my voice to the multiple submissions thing. I sent mine out in batches of a half dozen or so at a time, doing another bath every week or two weeks, as the rejections came in. Doing it that way enables you to tweak your submission in the light of comments received - but always to feel you have some submissions 'out there'. And meanwhile I got in with the next book - partly to soften the psychological blow of all the (inevitable) rejections. It meant I could kid myself into thinking, 'Oh, that old thing...!'
I'm sure you have done this, but a good way to select agents (apart from the genres they say they represent, on their websites as well as in the WAAYB) is to find out who represents the authors you admire in your field, and approach them first. Authors often include their agent in their acknowledgments, which is a good source - or try querytracker or similar sites which tell you who represents whom.
http://querytracker.net/clients.php?g=T
(By the way, not sure I said - welcome to WW!)
Rosy x