A biography
http://www.imagi-nation.com/moonstruck/clsc24.html
with links to online versions of Marlowe's works. There are also links. A no-frills place to start.
A beautifully designed Christopher Marlowe site.
http://www.luminarium.org/renlit/marlowe.htm
Quotes, works, bio, essays and articles.
The Marlowe Society home page.
http://www.marlowe-society.org/
An incredible site, put together by true Marlowe enthusiasts. A must-visit.
A page all about Doctor Faustus.
http://spider.georgetowncollege.edu/english/allen/meddram.htm
Wonderful for providing context, perspectives, and valuable information. Follow the links.
The Catholic Encyclopedia, compiled in 1908.
http://www.newadvent.org/cathen/
Marlowe may have been a Protestant, but the Catholic Encyclopedia is a free online resource providing great information on many subjects useful in understanding the background of the play. Look up "Satan," "Angel," and "Witchcraft" for starters.