arduino sound amplifier and motor

Hi,

Can somebody please help me how to combine sound level in mic and speed of motor.
I managed to control motor speed with potentiometer, and to do the project secret knock detecting lock (http://www.instructables.com/id/Secret-Knock-Detecting-Door-Lock/step3/Lay-Out-And-Test-The-Circuit/) but thats it, really cant think how to put it together.

I'm doing college project now, where people will speak or blow into microphone, and accorording to the volume level, motor suppose to spin faster and turn some paper platform connected to it all 360 degrees.

Can somebody please explain me how to do, and even better if you have any pictures or codes of similar staff.

I bought simple sound amplifier and soldered everything together.
It has gnd and in, - and + and gnd and out. I'm really not sure where to connect it. I tried to connect microphone to gnd and in, - and + to breadboard, but still confused about gnd and out? does it suppose to go to 5 v and ground on analog or not?

Thanks

Olesya