If you download firebug for firefox, it’s an addon. You can right click an element and see the styles applied to it. You can also see the HTML structure. It’s quite a useful debugging tool.
The column1/2/3 would all be floated, with columnParent being overflow:hidden to contain the floats. Rest is really just straightfoward :).
Oh well, im sorry for not being enough specific but I meant how the footer becomes down on the screen and to the sides wheter your screen is small or big or how much u zoom in and out, You understand me?