how can i add more motors to work for the arduino

Using Arduino Motors, Mechanics, Power and CNC
38

+----[Motor1]-----+
| |
+------------+----[Motor2]-----+---- 9 VDC
| | | (i used a nine volt connector clip so i connected + to motors and - to THE GND WERE THE EMITTER IS CONNECTED TO)
|
| | |
| +-------->|-------+
| Flyback Diode ( i used a 1n4004 )
|
/ Collector
Base /
Arduino Digital Pin 8 --------////--------[NPN transistor]
1k resistor \ (i used the TIP120 DARLINGTON TRASNSISTOR)
(i used a 1K resistor 1/2 watts 5% tolerance) \ Emitter
|
|
|
+---------------- GND
HERES THE PROGRAM I USED
#define LED 8

void setup()
{
pinMode(LED, OUTPUT);

}

void loop()
{
digitalWrite(LED, HIGH);
delay(10);
digitalWrite(LED, LOW);
delay(10);

}

thank you very much for your help