Potentiometer controlling position of stepper?

Could anyone help me out with a code for controlling a stepper motor
by the position of a potentiometer?

What I want to do is have the stepper position be directly related to where the position of the pot is, eg if I want the maximum turn of the stepper to be 200 degrees, then make that relate to the highest value of the pot, and all points in between be equivalent.

Also, when the pot moves in the other direction, I would want the stepper to turn the other way.

So, I am not aiming for the motor to be turning constantly. The only time it would turn is when the pot is turned. And the speed (say from the starting point of 0 degress to 200 degress) would be as fast as you turned the pot.

What would the best value of resistance be for the pot? I am guessing that it would not matter, as you would state the value in the code?

I am using a bipolar stepper (4 wires) and I have got a dual H bridge.

Is anyone able to help me out with programming this? I am pretty new to Arduino programming, and this would be a big help.