From my buddy Webster:
agent: somebody who officially represents somebody else in business. Guess where the word agent is derived from. To drive, to act, to do. Hmmm, I found this when I looked up the word agent and I thought it was so interesting. This is exactly what an agent does. He/she drives your book around to lots and lots of publishers. This is why I feel most writers who are serious about becoming published need the expertise of an agent. They have your back. They're there for you.
Remember that they work for you. But as good as they are, they need a revised, polished book from which to work with. I am writing this post, because I just told a writer that her work is not ready. She needs to find her inner editor and go through the entire book again. And she needs to get a beta or two to read and make comments on her book. Then when the book is wonderfully refined. Then and only then will it be time to do the agent search. She understood. She knew deep down that she wasn't ready. I've made that same mistake. Wanting an agent so much that I queried too early. But. I stopped after three or so and made the book stronger.
Agents aren't miracle workers. Only God can do that. But they are worth their weight in gold. Just be sure you're ready. Really ready. :) A polished book, a sparkling query letter, and fingers that are crossed. Tightly!