There are a lot of published handbooks on bookbinding and repairing damaged books. The ones I have looked at seem pretty similar and Laura Young's handbook is no great exception. It is, however, among those that are fairly complete in the coverage of bookbinding, but less complete in the coverage of book repair. In any case, it is admirably informative and readable, including several photographs and numerous clear drawings that illustrate various techniques.
There are chapters on book structure, binding styles, equipment, and materials; but the heart of the book describes various techniques for assembling and binding a book from scratch. In the course of this, one comes to understand the component parts of a book and can recognize how minor damage might be repaired. A later chapter provides more explicit advice on conservation methods, but even here, the treatment is brief and insufficient to give one confidence that one might not do more harm than good in repairing a book.
Young is fairly good about not expecting the reader to be acquainted with bookbinding jargon, but the novice reader might do well to have on hand a glossary of bookbinding terminology. ABC of Bookbinding: A Unique Glossary with over 700 Illustrations for Collectors and Librarians (also published by Oak Knoll Press) is a good choice.
Interestingly, YouTube offers a number of valuable videos on bookbinding and repair that may well make handbooks of this sort obsolete.