The Math League
The Math League: Percent & Probability
This tutorial gives definitions and examples of percents and probability and covers percent as a fraction and percent as a decimal.
Lawrence Hall of Science
The Math Page: Skill in Arithmetic: Multiplying and Dividing by Powers of 10: The Meaning of Percent
This excellent math resource explains and defines the meaning of percent. Multiplying and dividing by a power of 10 is incorporated as a preview to understanding scientific notation.
Lawrence Hall of Science
The Math Page: Skill in Arithmetic: Percent With a Calculator
This tutorial explains how to use a calculator to find a percent. There is also a practice section at the end of the lesson.