LibGuides: Finding Book Reviews: Websites

Amazon
Sells mainstream book reviews.
Google Scholar
Search for book reviews
LibraryThing
Informal book reviews by readers.
New York Review of Books
The New York Review of Books is a semi-monthly magazine with articles on literature, culture, economics, science and current affairs. Search the archives from 1963.
New York Times: Book Section
Search the newspaper's book reviews from 1981 and on.