Ask your instructor to show you how to go through the drawing tutorials
http://wikihelp.autodesk.com/Inventor/enu/2011/Help/Tutorials/123AutodeskInventorTut/3640Drawings
if you have trouble with a step in the tutorial - post back with questions where you get stuck.
Then we can move on to your specific problem once you know how to start a drawing (idw or dwg).
A big THANKS to all of you.
At last I have figured out how to get the orthographic views from a 3D drawing.
I need to open a drawing file and place the 3D model at required positions. That's all.
You guys were saying this, but I was not able to understand it.
Anyway, thanks a lot.