Thomas' Calculus  
   Discussion on the development of mathematical concepts in Euope and Egypt from 500 BC to the year 2000 AD. Includes timeline, topical essays and biographies of mathematicians.
   http://occawlonline.pearsoned.com/bookbind/pubbooks/thomas_awl/chapter1/medialib/custom3/deluxe-content.html

The History Of Calculus  
   Topics include the discovery of infinity concepts by Zeno, area approximation methods, Descartes' approach to finding normal lines, and finally Newton and Leibniz proving The Fundamental Theorem of Calculus. Time period discussed is from the 5th century
   http://www-gap.dcs.st-and.ac.uk/~history/HistTopics/The_rise_of_calculus.html

Earliest Uses of Calculus Symbols  
   Gives background for notations that are commonly used like the integral and delta signs.
   http://members.aol.com/jeff570/calculus.html