For more info on PWM, watch
from 1:40 onward.
With servos, you actually do not need to regulate the voltage for them. In fact, if you just plug your servo's power into the Vin pin on your Maple board, hook up the servos ground wire to ground, and attach the signal wire to one of the Maple's PWM pins, your servos should work just fine. Make sure you double check your servos rated operating voltages, because the maple board takes an input from 7-18v. A servo like the HS311 has an operating voltage of 4.8-6 volts.