Once you have the code, you can connect all the external parts. The easiest way to do this is with a breadboard. This will let you make temporary connections to test everything out.
Connect the motion sensor to the 5V pin, the GND pin, and to digital pin 13. Connect the black wire of the buzzer to GND and connect the red wire to digital pin 2. Lastly, connect one of the resistors to the 5V pin and analog pin 5. Connect the other resistor to GND and analog pin 5.
Before plugging in the Arduino board remove one of the resistors from the breadboard. Then connect the Arduino board to your computer with a USB connector cable, and upload the code. Once the upload is complete the system should immediately begin functioning.
To arm the system, insert the resistor back into the board where it was. After it has been securely fit in place, remove it again. As soon as the Arduino detects the resistor, it will begin activating the alarm. After a ten second delay, the motion sensor will be activated. When motion is sensed, there will be a brief warning beep and ten seconds later the alarm will sound. To deactivate the alarm, insert the resistor back into the breadboard. The alarm should stop immediately, and after two seconds, the alarm will be deactivated. You can now either remove the resistor and the alarm will go into standby mode (de-activated) or you can leave the resistor in and the system will reset.