EconLit has book reviews: look under the "limit your results" section, see the Publication type box, and select the book review option. ABI/Inform includes reviews of business books: at the search screen, see More Search Options > Document type > Review.
JSTOR will search over 200 business publications when you select Advanced Search and pick "business" as a topic. Must select 'Review' as 'Item Type' in the 'Narrow By:' section.
You may also find 800CEORead, a blog about business books, to be useful.
Text us: 314-582-0194
Call us: 314-977-3087 
Walk in: Mon-Fri 9 am-5 pm 