use of pins 0 and 1

can I use pins 0 and 1 on the ardnuio for example lighting an LED and will this interfere with the data communications?

You can use the pins 0 and 1 for LEd lighting but when you will load the software in ATmega of your arduino then they will blink unexpectedly as the 0 and 1 pins are receiver RX and Tranfer TX pin's so when you Arduino makes connection via. serial with the computer they will be used by the Chip to communicate(transfer and receive respective data/info).

Assuming you are using a Uno or similar design, using pin 0 to drive anything with a resistance less than about 4K may stop the bootloader working. This is because it's driven from the output of the USB-to-serial chip via a 1K resistor. If you're prepared to disconnect your LED from pin 0 when uploading sketches, then go ahead and use it.

Pin 1 doesn't have this problem because it's normally used as an output anyway.

You may wish to put print statements in your sketch to help debug it, as the serial data uses those pins you are best to avoid them for use in your circuit.

My rule about pin 0 and 1 is : Dont TOUCH or USE those pins except for communicate with the on-board USB chip.

Techone:
My rule about pin 0 and 1 is : Dont TOUCH or USE those pins except for communicate with the on-board USB chip.

I agree they are the last pins you should use, but sometimes you need all the available I/O pins.

Also good to know is that you can use the analog pins as digitalIO too which is often forgotten.