Here's Thomas Bulfinch's discussion of Pythagoras.
Pythagoras - The School of Pythagoras
Features a collection of book reviews, bibliographies, videos, and commentary related to Pythagorean theories of numbers.
Pythagorian School - Ancient Natural Philosophy
Profiles the Greek philosopher Pythagoras of Samos and details the scientific, theological and political developments credited to his school.
The Presocratic Philosopher Pythagoras
Pythagoras of Samos is the most familiar of the Pre-Socratics, yet we know surprisingly little about him.