Welcome to the community @arif - I've not used Processing myself as my background is generally more technical. I think it's commendable that you've set your goals on something more low-level (closer to the hardware) to further your knowledge and skillset.
I learned C++ at the university, and from simply picking up tricks and tips all over the internet as I've progressed. I'd say my biggest concern regarding your ambitions is biting off more than you can chew. While Cinder is, in my opinion, well thought out and designed and generally gets completely out of the way to let you do whatever you want, you've hit the nail on the head in regards to lacking documentation. I wish I could recommend a good book, but the one I voluntarily reviewed lacks exactly the stuff a guy like you would want - some background info on choices based in C++, rather than in Cinder.
I think my recommendation would be to complete a series of non-Cinder tutorials just to get a better grasp on C++ and OpenGL in general. Cinder helps you do so much, so much faster, but if you're fairly clueless as to the underlying nature of the elements it gives you, I think you'll often find yourself in a world of confusion as to why one part of your program seems to be adversely affecting another part.
Not sure if that helps...