Website that rates age-appropriateness of books?

[laurabfig]

My 8 year old is able to read far above her age-level, and some of the books she is bringing home from the school library seem to be questionable content-wise for her age, even though she is able to read them.  Does anyone know of a website that rates the age-appropriateness of a book's subject matter?  I'm thinking of something similar to the common sense media ratings that netflix gives to movies.  I'm just going to read some of this one she brought home, but surely I can't keep doing this for every book that she wants to read! :)

[laurabfig]

ok, never mind...commonsensemedia.org is great!  they have books too! (and the one she checked out was rated for 13 and up!!!...won't be reading this one for now...)