Seems documentation on this shield is hard to come by. So, here are a couple of points to add about the the schematic in the link above.
It does not show the jumper by the power header. This jumper is very important.
When the jumper is disconnected there are essentially two separate power supplies for this shield. Putting power in through the VCC header will give you whatever power you put in back out to the servo controllers V pins (these are labeled Digital IO Ports D0-D13 on the diagram and are outlined in light blue). All other V pins anywhere else on the shield provide 5V from the Arduino 5V pin. There specs http://www.hobbyking.com/hobbyking/store/__24778__Arduino_Sensor_Shield_V4_digital_analog_module.html
indicate that you can send in 6-20VDC in on the VCC header.
However, when the jumper is connected (the out of the box default), the VCC input in the header is connected to the 5V power pin from the Arduino. This means two things. Number 1, you do not need to put power into the VCC header at all, all V pins on the shield including Digital IO pins will give 5V powered from the Arduino 5V pin (assuming that the Arduino can supply enough current for your needs). Number 2, if you do provide power into the VCC header that is more than 5V, you can fry your Arduino.
Please do not ask me how I know this last one... Ah, If I had only spent a few moments using the continuity test feature on my DMM before I fed 12V into this shield. Oh, well, burnt hand teaches best and all that. I hope this post saves someone else from making the same mistake.