Search for journal articles on most topics. This multi-disciplinary database is a good place to start if you don't know where else to begin. (EBSCO)
If a book is in the UR library collection, the record in OneSearch will typically include book reviews found in the publications that specialize in book reviews and in some general interest publications. If we do not own a book, you can often find a review in Books In Print, especially for trade fiction and general interest non-fiction. For reviews of scholarly books, databases focused on the appropriate subject is often a better place to search. Reviewers often disagree, so it is better to read several, if they are available.