Curves Question

I'm fairly new with using Photo CS3 Extended
But I have a problem with only one aspect of the program
Which is Curves
>.<

I know how to use Curves
But for some tutorials they have two points of color
i.e. RGB; Input#1: 76 Output#1: 34
Input#2: 120 Output#2: 96

And they will have it like that for RGB, Reds, Greens, and Blues
So my question is;

How do you do the other inputs and outputs?