Books reviews are important in the research process because they can give you important information about significant studies on the topic or field you're writing about. A lengthy, well-written book review summarizes the major findings in the book and evaluates the book as to its coverage, accuracy, and authoritativeness. When you search the Library's periodical databases, you'll find lots of book reviews, which can lead you to books you might wish to consult and can give you valuable perspectives on your research.
The most substantial book reviews of academically-oriented books are published in scholarly, peer-reviewed journals. These reviews are written by scholars in the field and will often cite other books on the same topic. The example under the "Searching for Book Reviews in Academic Search Complete" below shows how to search for these kinds of book reviews.
Other book reviews are less in-depth, but can still be valuable to you. These reviews are published in newspapers and popular magazines, like Time or The Atlantic. Certain books reviews published in newspapers or special sections of a newspaper, e.g. New York Times Book Review, are often written by specialists, other authors, or journalists covering a particular field.