Stage widths and Heights

I am still a little fresh with understanding stage.width and stage.height I do understand parameters like’/2’ divide the stage in half and centers your MC and ‘-85’ will push your mc to the right side but I have only really been playing with numbers and don’t really understand their true meaning. Does anyone have any documentation on this so I can actually understand what numbers will place mc’s where?

Also I am trying to figure out the resize aspect of it as I would like to make a fluid fullscreen layout that animate all the mc’s into new proper positions on screen resize. Problem I am having though is every time the window is resized all the mc’s fall back into their original position set when the movie first loads.

Any tutorials or documentation on this would be great as I am not finding much on the net.