Here's some simple rules to remember for logarithms.

log(base b) x = y can be rewritten in exponential form as b^y = x.

 Ex)  log (base 3)9 = 2 is the same as 3^2 = 9

ln x = y is the same as log (base e) x = y, which is e^y = x.

A natural log is basically a logarithm with base e, where e is approximately 2.718.

The log of a product is the same as the sum of logs.

log xyz = log x + log y + log z

The log of a quotient is the difference of the logs.

log x/y = log x - log y


Another useful rule is log x^2 = 2logx.  Basically the exponent can be moved in front of the log.

These basic rules will help anyone when trying to solve problems with logarithms.