To find manga, use "manga or graphic novels" and "Japan" as keywords and limit to books or "Comic books, strips, etc. -- Japan" as a subject search.
For research on manga, search "Comic books, strips, etc. -- Japan -- History and criticism".
Frederik L. Schodt's HomePage
Homepage of the author of several books on manga; includes descriptions and tables of contents from his books and a good set of manga links.
"Manga" entry, Wikipedia
Brief overview of manga, including origins, format, style, types of manga, manga distributors, manga magazines, etc. (Note for those unfamiliar with Wikipedia: this source is a free-content, collaborative website designed to be written, updated, and edited by its readers. The content of any Wikipedia entry can change at any time. All content should be verified.)
Formerly the Shoujo manga page. Created by a cultural anthropologist in the Department of Cartoon & Comic Art, Kyoto Seika University
Tezuka Osamu World
Official web page. Includes links to Tezuka Osamu museum, fan club, and information on the man himself.
Ohio State's manga blog
Provides an index to the manga titles held at Ohio State (over 1300).
English translations of manga are held in Lilly library while Japanese manga are in the East Asian Collection on the second floor of Bostock. Most are in the PN's but some are classified by subject (history, economics, literature).