Scene duplication and Non-Identical Materials?

Okay, I think I’m on the right track to get what I need, but I’d like to make sure because there’s little worse than going halfway into a project only to find out the method you’ve been using was wrong.

I need to duplicate the objects, motions, rigging, and basically everything that has nothing to do with the colors of a scene multiple times, then apply different materials, textures, light colors, shading styles, etc to each duplicate. I think this can be done by duplicating the scene and making sure to link the objects when I do it. I think. I think I then go on to (somehow) unlink the materials, textures, and light colors of each scene so that they are independent of each other but leave the objects (including shape, positions, etc) linked. Somehow.

As you might be able to tell, I’m not entirely certain how to get done what I need done. I’ve tried looking for exact explanations of how to do it, but I don’t really understand them since I’m still so new to Blender. It seems like it should be intuitive, but near as I can tell it’s actually fairly complicated. I am absolutely certain that I’m on the right track though.

So, the questions, I think, are:
What is the correct way to duplicate the scene to get objects that use different materials, textures, and shading but are otherwise identical and synchronized? And can detailed step-by-step instructions be provided for this?

Like if I wanted to duplicate a cube, have the duplicate be shadeless red and the original shaded gray, but when I change the position of the original OR the duplicate then both cubes now use the new position. (Yes, I know that’s a fairly trivial example, but since I 'm still so new to this I’m hesitant to try to create a more elaborate example situation, even though I will definitely be using this for fairly complicated scenes)