1. You should just completely forget about windows specifics for now , try using SDL it's pretty easy and makes a nice place to start when trying OpenGL.
http://gpwiki.org/index.php/C:SDL_OGLImmagine OpenGL just draws triangles with textures (it does way more then that but you shouldn't concern your self with that yet)
2.As i said , forget about it , use SDL for now. Some people just like to torture themselves.
3.OpenGL is crossplatform (works on linux, bsd, windows, mac os x to name a few, and some popular consoles have a very similar ogl based apie like the PS3 has PSGL which is based on OpenGL) , and has binding for alot of languages. (python , C/C++ , pascal, C#, java, etc...)
it's the initialization part that varies accross platforms , but again just use SDL , and don't bother with the rest)