Gravity calculations for falling object

I need a little direction on how to handle gravity.

What is the best way to implement acceleration due to gravity for a falling object? More specifically, how should each check/iteration on the object be done, if it should be done in that fashion?

h = 16t^2 + s can be used to calculate how many seconds the object will take to fall, and the objects height at any given second.

Would it be best to do a check every... say, 1/10th, or 1/100th of a second and place the object where it would be according to the formula, or would this approach be completely wrong?

I'm interested to know the different ways to accomplish this, but haven't been able to find anything substantial regarding this using google. Thanks for any replies.