I started reading Axel-Tobias Schreiner's 'Object-Oriented Programming
with ANSI-C', found via Marvin's link. The title made me enthusiastic
for a moment. I like C. But for OOP? It's a lot of dull
administration.
You could also consider not to use OOP. It has become very fashionable because of Java and C++, but there other paradigms working very well. C has been working for decades; why would you want to use it in a way it has not been conceived for?