OpenGL 3.x and OpenGL 4.x came out all of a sudden, but not many people made the switch. Here you will learn how to create a window with an OpenGL 3.2 capable context, which can be used as a basis for further tutorials.
Re-shaping a window with an OpenGL context can cause undesired scaling if not done correctly. If you wish to learn how to fix this, then this tutorial is for you. Learn how to setup your projection matrix with a viewing angle and both near and far planes.
If you wish to learn OpenGL, then this is the very first tutorial for you. Learn how to create a GLUT window with an OpenGL context, and how to initially setup OpenGL.