homework and exercises - Integrating for speed

Trying to determine the speed of a falling body with respect to traveled distance and initial speed. I've been provided with the following equation for acceleration as a function of distance and the grav. parameter(constant) of the attracting body :

$a=GM/r^2$

Where:

$a$ - acceleration.
$GM$ - gravitational parameter(constant).
$r$ - distance to the attracting body.

I have entered inputs for $GM$ and $r$ and integrated this equation with respect to $r$. This obviously yielded total acceleration per traveled distance, in other words $m^2/s^2$ at the given altitude.

How do I proceed to determine speed at this altitude?