To set up the steps per unit you need to know the motors steps per rev, that is most likely 200 but you can also get steppers that are 0.9 degree, so 400. As said however most likely 200.
You then need to know the microstepping. Also any gearing and finally the pitch of the screws.
If setting up in Imperial units then it would go something like this.
I will give some numbers for this example, yours will be different and only you can say what they are.
200 steps per rev of motor x microstepping of drive x gearing x number of turns per inch of the screw,
so
200 x 10 x 2 x 5 = 20,000steps per unit.
As said that is just an example of how to calculate, your hardware and settings will dictate what numbers you will use.
There is an alternative and that is use the Set Steps button on the settings page, its just above the Reset button, using that method will only be as accurate as your measuring.
Velocity and acceleration will be trial and error and I can really take a guess at that as it is all hardware dependant.
Hood