Tutorials for Learning C ?

During most of programing experience I used C# and python.I decided to take on C after I finished an intership working with C++.

So I am looking for tutorials and I am willing to blog about my experience of what I am learning, so I can contribute/modify/extend Zeitgeist, Shell, Mayanna and Tracker.

Here is one of the tutorials I am following but I could use more if possible. Feel free to link me with more tutorials. Does GNOME have a tutorials or a collection of tutorials for other programing languages?