• My favorite book reviewer: Randy Bauer. See his reviews here.
• Very good reviews can be found on  Hannon Russells ChessCafe.com.
• Tim Harding's page - John Elburg (not recommended) and Tim's own reviews (much better).
• You can also find book reviews in the Archives of the Correspondence Chess News (John C. Knudsen & Co.)
• John Watson (one of my favorite authors!) - at TWIC (This Week In Chess).