This is a simple setup to use the serial console in the Arduino Enviroment software. See more details in this blog post http://sjsdlabs.tumblr.com/post/47807176974/serial-input

serial_inpit

void setup(){
  Serial.begin(9600);
  for (int leds = 10; leds < 14; leds++) {
    pinMode(leds, OUTPUT);
  } 
}

void loop (){
  if (Serial.available()) {

    char ser = Serial.read();

    switch (ser) {
      case '0':
        trigger(10);
        break;
      case '1':
        trigger(11);
        break;
      case '2':
        trigger(12);
        break;
      case '3':
        trigger(13);
        break;
    } 
  }
}

void trigger(int pin){
  digitalWrite(pin, HIGH);
  delay(75);
  digitalWrite(pin, LOW);
  delay(75);
}

See more details in my this blog post http://sjsdlabs.tumblr.com/post/47807176974/serial-input