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. Pay attention to the options of selecting other books with the same subject headings and general call numbers which will help you locate additional materials when you have found one source which is useful.