I have not yet made any contact with an agent, though I plan to in the near future. My best suggestion would be to get a copy of the "Guide to Literary Agents" series of books. They're pretty expensive if you want to own a copy, but the newest versions are always available at your local library. The book gives a lot of good tips about what you need prior to contacting an agent, and a list of agents in the genre you're looking to get into.
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