Blinking of an LED is continuously changing the state of led that's mean to On and Off. Since the Arduino has its pins high at 5V and low at OV so it easily can drive an LED. Lets start with the circuit. Here is the systematic of the circuit made on Proteus ISIS.
I have connected the LED to pin 13 and a resistor of about 220 Ohm is connected in series with led and the connected that to ground.
I have connected the LED to pin 13 and a resistor of about 220 Ohm is connected in series with led and the connected that to ground.