Do you need an agent to publish a book? YES. Find one in the following ways:

A. Consult your personal network

B. Find books similar to yours, and see which agent they thank in their Acknowledgments

C. Consult Jeff Herman's Writer's Guide to Book Editors, Publishers, and Literary Agents: Who They Are! What They Want! and How to Win Them Over! Not only are the agents carefully pre-screened for this directory, Herman includes such revealing information as their hobbies, favorite books, former occupations, etc, so that you get a sense of who they are. When I conducted my search, I tried to find someone with whom I actually had something in common -- and couldn't be happier with the results.

Good luck!