If you don't have any belt reduction or anything between your motor and screw and you have a servodrive with 4X quadrature decoding (most common) you get 1200 steps per rev. So 1200 steps will give you 5mm and 240steps will give you 1mm...(1200 / 5 = 240)
The acceleration and velcoity tuning is mostly done by trial and error.
Have you looked at the Setup Tutorial on the MachSupport website? It should cover pretty much everything.