You can conduct a simple search by typing your search term or terms in the navigation bar at the top right of the screen. Please note that to search for a phrase you need to include them in quotation marks otherwise each term is searched for individually. For example: "United States" rather than United States.
On the left side of the search results page is many different filters, called facets, which you can use to help narrow your search. These include: Subject Area, Readership Level, Recommendation level, Review Date range, Format, Outstanding Academic Titles, and Community College Titles. Once one of these filters is applied it will apear at in a small box at near the top of the page. The clear the filter you can either click on the little "x" in the box, or click on the "Clear Results" Button.
Once you have found a book you are interested in you can expand your search to other relevant values by clicking on any text highlighted in blue in the entry. In this way you can find reviews for all of the books by a particular author. Other fields that can be searched include LC Class, Reviewer, and Subject.