I am by no means volunteering to write such a book, but I did not find Gunderloy's Painless Project Management with FogBugz to be very useful. I forget all the reasons I didn't like it, but I suspect it is because it was not the book I wanted to read when I got started with FogBugz. I remember finding it uninviting and uninformative, and it only gave the "10,000 ft view" rather than providing any useful insights into how to tailor FogBugz for use at a new installation. Of course, the latest version of FogBugz does provide many more tools for customization.
I am curious to see what other people think should go into a new book on FogBugz.