Here are sample book reviews.
1. Sample book review
2. Sample book review
3. Sample book review

Here are some good articles on how to write a book review.
http://www.well.com/user/ladyhawk/bookrevs.html
http://courses.washington.edu/tande/book_reviews.htm
http://library.queensu.ca/inforef/bookreview/write_review.htm
http://www.uleth.ca/lib/guides/write-review.asp
http://leo.stcloudstate.edu/acadwrite/bookrev.html
http://papa.essortment.com/bookreviewswri_reuc.htm