Step 2: The Sketch
For all of you that aren't familiar with a lot of technology terms, like myself, a program for an arduino is called a sketch. I assume that most people that are making this have already downloaded the arduino software but in case you haven't here is a link to the site where you can download it:
Once you have downloaded the software, open it up and start a new sketch. Next, click file, examples, digital, and blink without delay.
We are going to tweak this sketch a little. Go to the place where the sketch says "const int ledPin=13;" and change it to say "const int ledPin=12". That's it!