Arduino into processing

Hey, I’m new to arduino and processing and I need to do a project for my class that involves both. It is such a newbie thing to ask but everyone has to start somewhere right. Ok, my project is basically a voice recorder that I made in processing and I want to control the two “keypress” using buttons in arduino. I’m so confused whether to run the code out of processing or arduino or both. All I need is maybe an example code that demonstrates a step by step guide on how to connect the two programs. If someone could maybe email me, or post a response to this with a link to somewhere that shows this, or a guide to doing it I would be greatly appreciated. THANKS

run the code out of processing or arduino or both

Each needs its own individual software.

Examples at:-
http://www.arduino.cc/playground/Interfacing/Processing