Common Sense media is a great site for reviews of books, movies, TV shows, and music for your kids. Parents can review and give info to help you make wise decisions about which media your kids consume and what might be age-appropriate for them.
I often go to this site if I have a question about the maturity level of a book a student may be checking out of my library (a 5th grader generally is not as mature as a senior in high school).
Olmsted Library 