Hi I have made up a simple interface for my Pi gpio and now want to turn a led on and off. I have tried the Cambridge University tutorial on this topic http://www.cl.cam.ac.uk/freshers/raspberrypi/tutorials/ but fail at the first apt-get command as my Pi will not allow the command. Can anyone suggest an alternative or explain why this problem is occurring? What I find is that there is little or no explaination of what the commands are doing and why they are needed. 
