There is good advice at notability guideline for books page for writing new articles about books, as well as updating existing book articles. A book is notable, and generally merits an article, if it verifiably meets through reliable sources, one or more of the following criteria:
The book has been the subject of two or more non-trivial published works appearing in sources that are independent of the book itself.
The book has won a major literary award.
The book has been considered by reliable sources to have made a significant contribution to a notable or significant motion picture, or other art form, or event or political or religious movement.
The book is, or has been, the subject of instruction at two or more schools, colleges, universities or post-graduate programs in any particular country.
The book's author is so historically significant that any of the author's written works may be considered notable.