Other
Brown Math: It's the Law Too the Laws of Logarithms
The laws of logarithms (which flow directly out of the laws of exponents) are discussed here. Combining logs with the same base and the Change of Base Formula are also explained in straightforward language for the reader.
Other
Principia Cybernetica Web: Logarithm
Short site with links to related sites on the topic of the Logarithm
Math Words
Math words.com: Natural Logarithm
A brief explanation for what the natural logarithm is. Shows how to write the natural logarithm of x.