Book reviews are written when a book or film first comes out. They are usually short pieces in newspapers, journals or online review organs. Put the title of the book in quotes, and select "review" as the document type. Look to databases help screens for more detail. Remember that contemporary reviews of older books may be found in print indexes. The following guide has a chronological list of sources for book reviews.
Note that academic book reviews (in peer-reviewed journals) take a lot longer to be published, sometimes as long as 2 years.