For this project, I’ll be using the basic photoresistor code!

/*
 * A simple programme that will change the intensity of
 * an LED based  * on the amount of light incident on
 * the photo resistor.
 *
 */

//PhotoResistor Pin
int lightPin = 0; //the analog pin the photoresistor is
                  //connected to
                  //the photoresistor is not calibrated to any units so
                  //this is simply a raw sensor value (relative light)
//LED Pin
int ledPin = 9;   //the pin the LED is connected to
                  //we are controlling brightness so
                  //we use one of the PWM (pulse width
                  // modulation pins)
void setup()
{
  pinMode(ledPin, OUTPUT); //sets the led pin to output
}
 /*
 * loop() – this function will start after setup
 * finishes and then repeat
 */
void loop()
{
 int lightLevel = analogRead(lightPin); //Read the
                                        // lightlevel
 lightLevel = map(lightLevel, 0, 900, 0, 255);
         //adjust the value 0 to 900 to
         //span 0 to 255

 lightLevel = constrain(lightLevel, 0, 255);//make sure the
                                           //value is between
                                           //0 and 255
 analogWrite(ledPin, lightLevel);  //write the value
}

I still have yet to receive my Lilypad Light Sensor, so I cannot confirm if this code is the best one at the moment. I may change this once I am able to experiment with the sensor!