University of St. Andrews (UK)
University of St. Andrews: Johann Peter Gustav Lejeune Dirichlet
A biography of Dirichlet's personal life and on his mathematical findings, mainly in calculus and number theory.
Other
Academic Info: Mathematics Gateway
This site provides a comprehensive index and general directory to math sites that will help students in the study of circles.
Other
Seton Hall University: Johann Bernoulli (1667 1748)
A great biography of Johann Bernoulli is provided at this site. An audio clip is provided, as well as a good list of primary sources.
University of St. Andrews (UK)
University of St. Andrews: Nicolaus(ii) Bernoulli
This site, which is provided for by the University of St. Andrews, gives a brief biography of Nicolaus Bernoulli.