In your Arduino IDE, go to File->Examples->SD and try the example sketch called ReadWrite.
Also have a read of the sticky at the top of the Storage section of the forums as that will guide you on how to format the SD card correctly. It's here:
In your Arduino IDE, go to File->Examples->SD and try the example sketch called ReadWrite.
Also have a read of the sticky at the top of the Storage section of the forums as that will guide you on how to format the SD card correctly. It's here: