Common Sense Media is a great web site that has honest reviews of media, such as movies. The reviews are not critic reviews, they are reviews about the content of the media and it's appropriateness for children. It does give you a rating about the movie's quality and it also lets you know what age group it is appropriate for.
For instance, "Paul Blart, Mall Cop", is listed as 3/5 stars for how good it is, and appropriate for age 12 and up. The reviews include details about violence, sex, language, consumerism, drinking, drugs, smoking, messages and role models.
There is a section for parents and one for educators.
The site also has a lot of information on how to educate children about media and the internet to help keep them safe. The educator's section has information and resources about cyber bullying, cell phones, sexting, and internet predators.
The site is a great resource for parents and teachers.