First of all, what you're looking for isn't really an engine. You're looking for a graphics API or a graphics API Wrapper to do your drawing.
I can recommend SFML. It's a C++ library that manages most of the basic things that everyone needs for you.
It features a relatively powerful graphics part which wraps around OpenGL, but also includes basic support for window-management, input (keyboard, mouse, joystick/gamepad), audio (playing sounds and music) and networking.
Since it's C++ and entirely object-oriented, it will be very simple to understand. For example, loading an image and displaying it more or less looks as simple as this (in SFML2.0):
window.Draw(sprite /*, myAwesomeShader Optional shader argument */);
Apart from the superior code-design, it's also a lot faster than the current version of SDL and has more features (if you use the basic SDL libs).
I can really recommend it if you're using C++.
Also, if you're going to pick SFML, start with SFML2 instead of 1.6. It isn't officially released yet, but it is going to be very soon and not a lot will change in the API until then. The latest SVN snapshots of SFML are always available on the download page.