Let’s face it, not all manga and anime are appropriate for all ages. Just like movies and video games, manga and anime have age ratings available.
Anime age ratings can follow the film ratings of the Motion Picture Association of America or the TV Parental Guidelines set by the Federal Communications Commission, but anime publishers may have their own age ratings as well. Here are some common ratings you may find:
Each publisher has their own age rating system, so definitely check with the publisher. However, most manga publishers will group their age ratings like following (but may not use this exact language):
Anime and manga are more than entertainment--they can make learning fun and get students motivated to learn outside the textbook. Teaching a class on World War II? Show the human element regular Japanese people experience with a screening of Grave of the Fireflies (1988).
Anime and manga visualize concepts and ideas in a medium that is easily accessible to students. Manga Guide to Statistics anyone?
Anime and manga reflect Japanese popular culture and cultural norms.
Trying to teach Japanese? Use anime to introduce speaking Japanese and manga for reading Japanese. Don't have time in the classroom? Encourage it outside the classroom. It's a great way to reinforce language learning.
You know those reference sources and buying guides for libraries...
500 Essential Anime Movies by 
The Anime Encyclopedia by This is just a few, but there is a ton out there.
With limited resources, you'll want to collect the best of the best. So start by looking at the award winning anime movies and series.
Let's face it--there are a few titles all libraries should have. Not a comprehensive list, but a starting place for libraries starting to collect anime.
You know those reference sources and buying guides for libraries...
Comic Book Collections for Libraries by This is just a few, but there is a ton out there.
With limited resources, you'll want to collect the best of the best. So start by looking at the award winning manga.