I Second DaWei's idea of putting it all in 1 big div, many designers use a wrapper div to keep things explicit and makes it easier to define child elements (simply put, it'll save you a lot of trouble).
As for the image at the top, it's hard to see, so it makes you focus (it looks like i've run my mouse over it and selected it). Then once you focus you see it's actually a bunch of images. Not good. If there's 1 area of my computing experience where I feel that open source will never win over commercial software it's in the graphic design arena. If you're going to use a bunch of images like that, it's fine. But you need to blend them together so it flows (even just a minimal fade like what I did @
http://ac-prods.com/ can work wonders for how people view the site).
The overall look of the design is good for a first one, but you need to spruce things up a bit before you go live with it.