My dad is looking for an agent for a [pop] medical/psychology/self-help book he has written. How would one find an appropriate agent for something like this?
I find lots of hits when I Google literary agent listing. Agent Query is one example. It lets you choose “self-help” off the list of nonfiction topics and then search for agents who rep that.
Or go to Amazon and search for books on literary agents. Several will come up at the top of the list. You may find some at a local library, but be warned that libraries tend to have older editions and that they date extremely quickly.
Follow any rules that the agent has listed exactly. If the agent wants queries then find how to write a good query letter and send only that. If the agent wants to see sample chapters, then send those. Most agents would not want to see the complete manuscript for nonfiction at first.
You can query multiple agents at once. If you get a serious response then give that agent a chance to look at the full material.
Never, never, never pay an agent money. Agents get a percentage of the advance a publisher pays. You do not pay them.
There are lots of guidebooks and books listing agents. The one I liked was Jeff Herman’s. I’ve forgotten the name–and it was old, so I got rid of it when I moved–but it’s updated yearly and lists what you need to know about agents, including who their clients are and what to send them. The others are similar. They cost about the same, and are mostly available at public libraries if he doesn’t want to spend $20.
There are also a couple of websites that list what agents are selling right now, and who they’re selling them to. One is Publisher’s Lunch, another is the Publisher’s Weekly website (you may have to have a subscription to get on here–I’m not sure).
But for nonfiction he might not even need an agent. A lot more publishers are open to accepting proposals for nonfiction books straight from the author. He can target where he wants to be published, and then find out (1) if they accept unagent submissions, and how to do that, or (2) which agents have placed projects there and therefore have a relationship with that publisher.
From the Writer’s Market people: Guide to Literary Agents
Find recent similar books, preferably successful ones. See if the author has thanked his or her agent.
Solicit that agent.