Jewish Encyclopedia: Hezekiah 
Overview of the king of Judah from the traditional Jewish perspective, including rabbinic commentary.
http://www.jewishencyclopedia.com/view.jsp?artid=700&letter=HHezekiah 
Passages about the Judaean king from the King James version of the Bible.
http://www.topical-bible-studies.org/48-0084.htm
Hezekiah 
Profile of the King of Judah from a joint Lutheran and Catholic bible study project.
http://www.aboutbibleprophecy.com/p82.htm
Catholic Encyclopedia: Ezechias 
Commentary on the Biblical king from the traditional Catholic perspective.
http://www.newadvent.org/cathen/05737a.htm
The Life and Times of Hezekiah 
A Christian analysis of the Biblical king and his importance to the history of Israel.
http://www.robibrad.demon.co.uk/hezekiah.htm
Jewish Virtual Library: Hezekiah 
Profile of the Judaean king, with links to pertinent Torah passages.
http://www.jewishvirtuallibrary.org/jsource/biography/Hezekiah.html
King Hezekiah (late 8th-early 7th century BCE) 
From "The Jerusalem Mosaic" created by The Hebrew University of Jerusalem. Includes historical facts, Bible references, and some archaeological photos of structures he had built.
http://jeru.huji.ac.il/eb34s.htm
Hezekiah in Chronicles and Kings 
A textual comparison of material about the Judaean king in two Biblical books.
http://fontes.lstc.edu/~rklein/Documents/hezekiah.htm