Japan: An Illustrated Encyclopedia. (Ref. DS 805 .J263 1993)
Kodansha Encyclopedia of Japan. (Ref. DS 805 .K633 1983)
Modern Japan: An Encyclopedia of History, Culture and Nationalism. (Ref. DS 805 .M63 1998)
Japan Encyclopedia. (Ref. DS 821 .F73 2002)
Encyclopedia of Contemporary Japanese Culture. (Ref. DS 822.5 .E516 2002)
A Dictionary of Japanese History. (Ref. DS 805 .G64)
Historical and Geographical Dictionary of Japan. (Ref. DS 833 .P3 1964)
Cultural Atlas of Japan. (Ref. DS 821 .C62 1988)
Japanese History and Culture from Ancient to Modern Times. (Ref. DS 835 .A1 D69 1996)
An Introductory Bibliography for Japanese Studies. (Ref. DS 806 .A1 I57, 1974-2006)
WWW-VL History Index - Scroll down about one-half way and you will find many links to history sites.
CIA World Factbook - Basic information about each country.
Japan - A Country Study - From the Library of Congress, this book provides extensive information on each country.
H-Japan - This site is good for discussions, forums and book reviews.
H-Asia - Ditto.
History of Japan: An Annotated Directory of Internet Sources
This is an outstanding collection of sites from prehistory to postwar Japan.
Internet East Asian History Sourcebook - There are three important "chapters" here: Traditional Japan; Japan as a World Power; and Postwar Japan.
Periods of Japanese History - Arranged by period from ancient times to the present. Each period provides an essay with many links.
History of Japan - This is a nice collection of annotated sites.
Texts and Documents
Hiroshima Archive - Mostly pictures.
Nagasaki Journey - Pictures and recollections of the bombing.
Atomic Bomb: Decision - Documents dealing with the decision to drop the bomb.
Maps and Atlases
Timelines and Chronologies