University of Wisconsin: H. Jerome Keisler's "Elementary Calculus, Chapter 8: Exponential and Logarithmic Functions, Section 8.3: Derivatives of Exponential Functions and the Number e"
Read Section 8.5 (pages 454 through 459). This chapter reintroduces the natural logarithm (the logarithm with base e) and discusses its derivative and antiderivative. Recall that you can use these properties of the natural log to extrapolate the same properties for logarithms with arbitrary bases by using the change of base formula.