The Readers' Advisory Guide to Graphic Novels by Francisca Goldsmith (2010)

ALA Editions, 978-0-8389-1008-5 

(from the website)

This guide includes

• A short course in graphic novels, along with reading lists and professional tools
• Tips on advising graphic novel readers on what to read next
• Suggestions for introducing graphic novels to those patrons unacquainted with them
• Advice on promoting your graphic novels collection

The Librarian's Guide to Graphic Novels for Children and Tweens by David S. Serchay (2008)

This is a pretty comprehensive guide with sections on the history and lots of definitions and explanations for librarians who know very little about comics. The Annotated Suggested Booklist has helpful age range recommendations and reviews. 

Getting Graphic!: Comics for Kids by Michele Gorman (2007)

It's getting to be a little dated now, but this little book is still great for those beginning to develop a kids' comics section.

Teaching Visual Literacy: Using Comic Books, Graphic Novels, Anime, Cartoons, and More to Develop Comprehension and Thinking Skills edited by Nancy Frey and Douglas Fisher (2008)

Building Literacy Connections with Graphic Novels: Page by Page, Panel by Panel edited by James Bucky Carter (2007)

This collection of academic articles focuses almost exclusively on high school education, but there are a lot of principles that could be applied to elementary education, as well as abundant additional resources noted in the bibliographies of the articles. It can be difficult to find academic studies on comics and education, so a book like could be a valuable resource on a number of levels.