Contents notes provide extra information about a book. A good way to generate useful keywords is to look for terms which appear frequently in your readings or discussions.
Bibliographies are a particularly good way to find out about primary source materials.
When dealing with broad topics, it is usually more effective to use a subject heading search rather than a keyword search. Subject searches assure you that the content of the book will concentrate on your subject. When a subject heading is assigned to a book, it is assigned at the most specific level. It is important to look under as many potentially useful headings as possible. Bibliographies are essential resources for locating research materials.