Alternatives to graphics.h
Take a look at Cinder. It's a C++ library designed for 'creative coding' and looks pretty simple to use while still being powerful (check the examples).
You could also try SFML. It has quite a following and you'll have a large community behind you should you have any trouble.
Allegro or SDL libraries may be for you.
I would also suggest not to use Bloodshed Dev-C++ as it is also a little outdated. You may use MS VC++ Express or Code::Blocks which are both free.