Processing with Arduino

Hey guys I have wondered this for a while now. How do you use processing with an Arduino? Do you guys know of any websites that have tutorials or can one of you help me right here? I want to make a little processing window on my computer that has a button. When you press it an LED turns on when you press it again it turns off. Any help you can offer would be appreciated. Thanks!

There are examples supplied with Processing that will get you started. They contain both the Processing code, and in comments, the Arduino code too. They are in the Libraries>Serial I/0 section of the examples.

Thank you so much!