There are many places to turn for leads on legit agents. If you have a writing community, start there. Share information with others who are going through the process: what agents are on their list? Whom have they already contacted? What kinds of responses are they getting?
Next, find out who represents authors you admire, either through the acknowledgments in their books, where agents are often thanked, or by Googling their names and words like "agent" or "represented by."
Finally, consider subscribing to Publisher's Marketplace, an industry newsletter, which announces books that have been sold, along with the name of the agent who arranged the deal. (For a fee, you may also access an online database of agents and editors.) Read the listings, and take note when a book sounds similar to yours. Poets and Writers also interviews agents periodically. If something an agent says in an interview resonates with you, consider sending them a query letter.
Return to the Agent FAQs.

