This book is awesome. IMO a must-read for every terrier owner because it's worthwhile even if you know most of this stuff already, but especially so for first-time owners who might not understand what sets apart these dogs and their natural, instinctual behavior so much from other types of dogs.
Also very important: it applies to some dogs that are not listed among terrier breeds by certain registries, but in their nature definitely do belong in this group, such as Dachshunds, Schnauzers, Pinschers, Feists, etc. etc. Link goes to the E-book, but a print version is also available.
TCDT really gives a thorough explanation on why, and in which ways, terriers are different from, say, retrievers or herding dogs, and how their specific instinctual behaviors can be influenced in a positive way though training exercises as well as management techniques to help the dogs behave more appropriately. IMO it does a great job of taking particularly useful exercises from many other, great training programs and applying them specifically to the terriers. If someone wanted just one good training book, instead of reading multiple ones (When Pigs Fly, Control Unleashed, and so on), this is definitely it.