Please refer the models shown below for instructions.

Automatic Street Light using BC547
Light Detector using LM358
Temperature Controlled Led using LM358
Police Siren using 555 Timer
Rain Detector using BC547
Melody Generator
Led Flasher using IC 555
Clap Switch
LED Blinking through Transistor
Display Counter
Controlling Led using Touch Switch
Object Detector using IR Sensor
Water Level Indicator