Really loving the color blocks; light green and dark grey on a white background unifies your color scheme, and definitely reinforces the image of your site as a "fun"/info-savvy portal. The white space is great for focusing attention on your content. I would consider changing the color of the yellow block though; perhaps to light grey. As it is, it's a bit distracting, hurts the eyes after reading for a sustained amount of time, and doesn't work very well for a background color. I would also look into making your social networking buttons bigger at the top of the page; paired with the black design motif in the background, viewers would probably overlook them. Perhaps a small floating sidebar with the buttons?