OneLoneCoder.com Javidx9 discusses a variety of computer graphics topics using his pixel engine. Go check out his YouTube channel that you can find on the website. It is great!
LazyFoo.net Site containing C++ with SDL 2 tutorials. Also includes OpenGL articles and lately even a lesson on using SDL with Android.
GameDev.net A long time running game development website with a nice forum for questions.
The Cherno A YouTube video series about C++ , OpenGL and 2D and 3D rendering.
Game programming patterns A book about game programming patterns, the online version is free but you can also buy it in print.
Geometric tools Dave Eberly has advanced articles on Math, Graphics and Physics.
Amit game programming A nice collection of articles about game development.