Mac OS X Disaster Relief was essentially an early version (for Mac OS X 10.0 and 10.1) of Mac OS X Help Line. Here are selected quotes from reviews:

This book is the best single source of OS X troubleshooting tips and techniques that I've seen! (Steve Becker, MacEase)

This is a book for the user, the frustrated user, the curious user and the user who wants to get the very most from the system. (ThinkSecret)

Mac OS X Disaster Relief is extremely well-written, refreshingly down-to-earth. (Ric Getter, MacDirectory)

Landau covers almost every known Mac OS X bug? much valued. (IT-Enquirer)

If you only own one book on OS X, this should be it. (Sherman Wilcox, Amazon.com)

This is one of those few books that are really worth five stars. Outstanding in every way. (Amazon.co.uk)