build these examples on your breadboard (and use the code examples provided in the links if you want.) Then try to create arduino sketches which do something different than the example sketches there.
LED + Potentiometer:
http://fritzing.org/projects/analog-inputoutput/
write an Arduino-Sketch which lets the LED blink in different speed, depending on the position of the potentiometer. Use the serial connection to monitor the values of the analog input.
Light dependent Resistor
http://fritzing.org/projects/photocell/
Use the same sketch as before, but use an LDR instead the potentiometer.
Let use the serial communication to see what values you receive, select different resistors and try again. Also measure the resistance of the LDR and compare to the resistors you used.
Buttons and switches
http://fritzing.org/projects/digital-input-button/
turn the LED on when pressing the button. Then turn the LED off when the button is pressed again. Note: The button bounces - use the delay function to debounce the button.