I received a complimentary review copy of this book, and, having been submitting for quite a while, I expected the agent listings might be slightly helpful for perusing agencies and agent names without the eyestrain of an internet database, at least for phase one of a search: identifying potential agents to query.
The listings are more helpful than I had anticipated. Sprinkled within the alphabetical-by-agency-name listings are "New Agent Spotlights" that highlight agents who might be hungry for new clients. I have found and been reminded of agents I plan to query, and there are a few listings for UK and Canadian agents as well.
It also includes an index by genre and the version I received includes a one year subscription to the FW online agent database (which I haven't yet used).
For those just starting out, I suggest cross-referencing agents you find in the book with the Absolute Write background forum. Search there by agent or agency name for not just potential warnings or conflicts of interest but also query/partial/full turnaround time anecdotes and the occasional new-client "Squee".
Then I would look the agent up on Agentquery to double-check submission guidelines/e-mail addresses for those who take e-queries, and to lead you to the agency website (if there is one) which often has submission guidelines in greater depth.
If the agent blogs or tweets, it never hurts to check their pages for something in common to personalize the beginning of your query letter.
As agents move between agencies and/or leave the business, listings will gradually fall out of date. This is another reason to check online before submitting.
The book also has conference listings. Conferences can be good avenues for learning from and pitching agents (and/or editors who are otherwise closed to unsolicited submissions). But they are not a substitute for learning to query, and query well and widely.
The front of the book includes great articles on how to write a query, how to write a nonfiction book proposal, the benefits of having an agent, the memoir market, copyright, agent and author perspectives, and more.
I thought "8 Ways to Write a Great Chapter One" by Elizabeth Sims was especially insightful for new and advanced writers alike.
Up until now I have been using online databases exclusively. I found, to my own surprise, that the book offers enough of a benefit in terms of organization, format and ease of use to be worth having on hand throughout the rigors of an agent search. The "recent sales" information alone is often difficult (or impossible) to find online (without perhaps paying for a subscription to Publisher's Marketplace).
If I'm still in the market for an agent, I will certainly buy a copy when my next MS is submission-ready.