PellesC is totally a 32bit compiler, so it cannot do any old-days 16bit DOS program, like graphic.h stuff. If u really need draw primitives, u have to learn some Win32 SDK instead (like : GDI). If u just can't do it.... i think u may need Borland C++ 5.5 (free, & 16bit).
if u search MSDN, there is many examples r written in C. i think u looked at somekind of MFC stuff, MFC is totally OOP & blackbox.....
GLUT lib can be download everywhere on the internet, just google it (it can use by PellesC, b'cuz PellesC is M$ lib compliant, how wonderful PellesC is !).