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/
This site has interesting information
about John Napier and Napier's bones.
http://gwydir.demon.co.uk/jo/numbers/machine/napier.htm
Napier:
http://www-history.mcs.st-and.ac.uk/~history/Mathematicians/Napier.html