Wikimedia
Wikipedia: Muromachi Period
Wikipedia provides information on the Muromachi Period of Japanese history running from 1336 to 1575. Also has a chart showing the Ashikaga family tree.
Wikimedia
Wikipedia: Onin War
Wikipedia offers brief information on the Boshin War, a Japanese civil war that lasted for ten years during the Muromachi period.
Other
Japan guide.com: The Muromachi Period
This site gives a brief basic overview of political rule in the Muromachi period.
Other
Eu: The Culture of Zen During the Ashikaga Shogunate
This in-depth site describes the role of Zen in the Ashikaga Shogunate thoroughly and describes many of the Shoguns' close relationships to Zen.
Khan Academy
Khan Academy: An Introduction to the Samurai
This article describes the rise and fall of the Shogunate in Japan. Included are pictures of Japanese art from these periods in Japanese history.
Columbia University
The Era of Wars: Onin War
In this page there is information pertaining to the Onin War and the factors that influenced it.
Other
Muromachi Period: Decline of Influence
This site describes the gradual loss of central influence by the Muromachi Bakufu.