Edit: the below is of no use now that the the OP identified his servo as a "ROB-09347 Large full rotation" servo, as it is a "continous rotation" servo.
I just want my servo to turn 90 degrees then stop. At that point I am done with the ardunio pro and would like to kill power to the servo until it is need the next show. I am running it off a 9 volt battery.
Time for somebody to start using the code tag # to put their code in a code box. Below is a way to have a servo move to a specific position in the setup portion of the code. Your request to "turn 90 degrees then stop" is not clear in reguards to how servos operate. You can move a servo to a specific position, but there is no feedback from the servo to the arduino as to the current servo position when the arduino starts up.
void setup() {
Serial.begin(9600);
myservo.writeMicroseconds(1500); //set initial servo position if desired
myservo.attach(7); //the pin for the servo control
Serial.println("servo-test-22"); // so I can keep track of what is loaded
}