From what I hear sdl is the most widely used. I'm using freeGLUT right now it's pretty good, and lots of tutorials cover it.
SFML is object oriented which the others are not. However its mostly meant to be a 2d platform and can get in the way if you wish to use it for a openGL window.
In order to get access to the openGL extensions use GLEW, its the most common, there are others like it but this one is what most the tuts use.
Also you will probably want a 3d math library glm will solve that problem for you.
Tutorials for modern openGL in order of my favs.
and an upcoming book you may want to buy