Gaming in C++

Here's the deal, /prog/. Over the winter break, I have decided I want to practice and expand my skills, and as such, design a small applet type game using C++. Now, i am fluent in C++, and MFC, but MFC wouldn't exactly be ideal for this. I fully intend for the game to be 2D Sprite based.

What should I look into, what should I use, and how should I go about things? I've heard openGL would work well, is there anything else I ought to remain cognizant of?

Define flexible. I am admittedly rather nub, having only done a small handful of visual projects, and never getting my hands on as much code as I would like. But I would intend for this to require at least some work, ie: no scroller shooters, simple top down games and such. I'm likely going to make a platformer, and see how much depth I could add, and something easily expandable. The fact that I haven't really worked with Visual C++ outside of MFC is probably the strongest indicator of where I currently lie.