[cdumler]

There is already one in place. It's called.. librarians. They do a lot more than just stand around a look pretty. There are degrees you can earn which includes things like how to manage tracking books and operate exchanges, managing catalog systems, training in computer use and learning, and... judging appropriate book content for readers. Librarians are much more than just someone who will help you with a book, if you ask.

[infotainment]

While that's true, I think GP's idea isn't necessarily a bad one. You could argue the same thing about game store clerks negating the need for ESRB ratings.