Help with a sketch to get a button to print a letter on a computer

Hi there,

I'm a complete novice at arduino & sketches but am fairly competent at electronics, computer stuff and software.
I have the arduino set up correctly and have uploaded the blink sketch successfully.

I'm looking for a sketch that will print a letter on the computer when I press a simple button.

At the moment I believe I have the correct wiring to achieve this:

5V going to the A side of the button
Ground going B side of the button through a 10k resistor
Digital pin 13 going to the B side of the button

I've based this on this tutorial: http://arduino.cc/en/tutorial/button

What I need is a sketch that I can compile and upload that will simply print the letter A when the button is pressed. I've scoured the internet and just can't find anything!
I know it's really simple but I don't know the language of the sketch yet and I need this to work!
Any help would be greatly appreciated!
Thanks in advance,
Mike

The Arduino IDE comes with a number of examples.
Have a look through them and see if you can find any related to the Serial object.