In a collection of critical essays, browse the Table of Contents (located near the front of the book) to see if any of the essay titles relates to your topic. For example, if you are interested in a particular female character in your novel, an essay about women in the author's works, might be relevant. Don't just look for the name of the character.
Similarly, use the Index (located at the back of the book) to find any pages in the book which have information relevant to your topic (primary source, characters, themes, etc.).
Note: Indexes (or indices) are not standardized. To find out if your literary work is included in any of the essays, browse the index to learn how it is arranged. Try looking for your topic under these entries: