bla: What does "taking the log" of something mean?
That is a very good question
If you take the log of 8 in base 2 the answer is 3 because
2*2*2 = 2
3 = 3
so the log of a number in some base is the power or exponent that would be accurate.
Take a look at this page, it is very good.
http://www.mathsisfun.com/algebra/logarithms.html