I really think you need a banner for your header instead of placing an ad there. There are better places for ads.
The left panel has a very long list of links.. I think you should remove the category section since its already in your menu. The subcategory is ok but I prefer a dropdown menu where the subcategory shows when I move my mouse cursor over the category.
The items in your homepage look a bit messy. The images have different sizes so the text are not aligned column-wise. I know you're trying to separate the categories into rows but its nice to see everything in uniform.