How do I start contributing to GNOME?

How do I start contributing to GNOME? I can program in C++ and Python, but have never touched C. I am not familiar with GTK even.

To be honest, I have no idea how GNOME works. All I have is a deep desire to somehow contribute to it.

Where do you recommend do I start? Any tutorial, mailing list or anything. I am ready to do the hard work, I just need a direction.

PS: I could have googled for the problem, but nothing beats the experience I have seen since Google returns SO for most of the questions.