How do I draw a text string onto the screen using GLUT / OpenGL drawing functions?
There are two ways to draw strings with GLUT
glutStrokeString will draw text in 3D
and glutBitmapString will draw text facing the user
If you don't like the built-in stroke font or bitmap font that comes with GLUT as per epatel's answer, you'll have to roll your own solution.
NeHe has some good tutorials (along with fully-working sample code) on this: