   Quickquestion
  If I set perspective view like so , gluPerspective(45.0,width/height,0.1,2500);Then in my draw scene, If I do glTranslatef(0.0,0.0,-5.0);I thought this would set the screen -5 units to the left ad 5 units to the right and 5 units up and down. ? How could I change the viewing plane so I know exactly how many units thereare on the left/right and up/down.   
  You are working in perspective so you will be able to see more and more in the distance the further you go away from the camera.  If you don't want perspective you should use, glOrtho   