Jintro on "[Theme: Thematic] Adding new div"

Here is a link to the online childtheme. It might not look like much, but it's a first try.
I've changed the layout since I asked this question, so there is no new div in the footer. However there is an added div (social_icons)in the header. I've managed to place it where I want it, but basicly by pure luck.
So long story short, any suggestions or tips are more than welcome!