could someone help me,,,,,
I am beginner in blender, how exactly to export .blend to OBJ file complete with the .mtl file attached to that file???

and could it be seeing on OBJ viewer???

I think you are in a forum new as well. Nobody click on a topic with a stupid subject like how???

Nobody??? I only clicked on your topic to tell it you.

One of the tricks for getting help is making it easier for people to help you. The other is asking in the right place.

A better title might mention exporting OBJ files. A better place to ask questions about using Blender are the user forums at blenderartists.org instead of here, at the developer forums.

Now for your question, there is an Add-on for OBJ import/export. You will have to enable it under File->User Preferences->Add-ons.

After that, it will appear under File->Export->Wavefront(.obj). You will need to have a UV-mapped texture on your object.