Alan Turing - http://foldoc.doc.ic.ac.uk/foldoc/foldoc.cgi?Alan+Turing Biographical entry in the FOLDOC.
Alan Mathison Turing - http://ei.cs.vt.edu/~history/Turing.html Undergraduate biographical essay by John M. Kowalik.
Wired Archive: Alan Turing - http://www.wired.com/wired/archive/people/alan_turing/ Stories involving Turing.
Alan Turing Papers - http://janus.lib.cam.ac.uk/db/node.xsp?id=EAD%2FGBR%2F0272%2FAMT Collection record of Turings papers at Kings College, Cambridge.
Alan Turing: Thinking Up Computers - http://www.businessweek.com/magazine/content/04_19/b3882029_mz072.htm Profile of the groundbreaking Cambridge mathematician. [BusinessWeek]
Alan Mathison Turing (1912-1954) - http://www.turing.org.uk/ British mathematician, cryptographer, and one of the key inventors of the modern computer. After his profound contributions to helping win World War II, he was persecuted for his homosexuality by his own government, and driven to suicide. Maintained by Turing biographer Andrew Hodges: extensive resources and links, online versions of several long essays on Turing.
Alan M. Turing - http://plato.stanford.edu/entries/turing/ Entry from the Stanford Encyclopedia of Philosophy by Andrew Hodges.
Turing Machine - http://plato.stanford.edu/entries/turing-machine/ Article on Turing Machines from the Stanford Encyclopedia.
The Church-Turing Thesis - http://plato.stanford.edu/entries/church-turing/ Article from the Stanford Encyclopedia.