[rhoads2234]

if you want it to only rotate 90 degrees, you will have to have some sort of sensor (limit switch, encoder or potentiometer) Be careful if you use a potentiometer- they have a limited range.

As for how to get a button to send signal to a motor,
use the "get" VI for a joystick and unbundle the button output (I recommend unbundle by name)
wire one of the buttons you want to use to a case structure (to the question mark) and in the true statement put a set speed for your motor. Create a constant for the speed.
wire the other button to another case structure and do the same thing, but your constant should be 0 this time.