Increasing and Decreasing Functions

I'm given the question:

"Suppose that "f" is a differentiable function with derivative f'(x) = (x-1)(x+2)(x+3). Determine where the function values of "f" are increasing and where they are decreasing."

A friend and I are trying to work out how to do this problem, and we're not having much luck. Our thoughts were to find the second derivative and then plugging in the x points from the first derivative to find where "f" is increasing or decreasing, but we're not having much luck.

Could some provide some insight as to the answer of this problem?