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