You need a Mosfet H-Bridge for Bi- directional control with a input circuit to read the pot and the uC in between.
If you don't know electronics and you don't know programming, do you mind if I ask why you took on this project ? How are you planning to complete it ? Are you expecting us to design and program it for you ? Is that your plan ? Don't you have anyone on your team who knows electronics or programming ?
JimboZA gave you this link back in DEC 2013.
http://www.ecs.umass.edu/ece/m5/tutorials/H-Bridge_tutorial.html
Why haven't you used it ? You question has already been answered 4 months ago
and you have not done anything with the information you were given then. Why should we spend any more time on this ?