This is one of the best all around sites that I have found. It is titled “The MacTutor History of Mathematics Archive.”
http://www-history.mcs.st-and.ac.uk/~history
This is an award-winning site that links to all sorts of mathematics information.
http://archives.math.utk.edu/
Throughout the text many mathematicians are profiled, and here I provide links to provide additional information for the interested reader.
George Polya:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Polya.html
Blaise Pascal:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Pascal.html