The basic setup of the circuits requires power and ground being connected from the Arduino to the breadboard.
Potentiometer:
Power is brought to the potentiometer, then connected to an analog input, then grounded. This setup allows for an unwired control over the corresponding LED. A digital pin connects to a 220 ohm resistor to the LED that is then grounded.
Button:
Power is drawn into the button, then connected to a digital input and grounded with a 10k ohm resistor. This allows control over the corresponding LED which is connected to a digital pin via a 220 ohm resistor, then grounded.
Photoresistor:
The photoresistor draws from power, then is grounded with a 10k ohm resistor and connected to an analog input. The corresponding LED is connected to a PWM digital pin, then is grounded.
