Your main homepage needs a lot of work from a usability perspective. You have 3 identical looking blocks that list different content. You should consider making them look different and restructuring that section of the page.
You also repeat parts of the navigation twice. Some of the links in the header are also below the login box. That's rather confusing as an end-user.
Finally, your right navigation block looks FAR too much like google ads. My eyes would be instantly drawn away from it
All in all it's a bit monotonous. It needs some colour, some contrast and a few more images here and there.