I think this is a wonderful design. I love the colors, the illustrations and the entire layout. Don’t add more pictures. You have a perfect balance as it is. Everything is so clean, and well organized, very very nice! Only suggestion I have is run your code through the validator. Your HTML has a few errors – you have your sidebar formated with the link around the image and h3, which isn’t valid. I suggest tweaking it and putting that sidebar into a list, and it have formatted like:
I realize that you probably are using the h3 for SEO purposes, but the strong tag is a good SEO keyword highlighter too (maybe not as much as an h3) but for the sake of code validity I’d rather be standards compliant.
Also, you’ve used the div id "footer-wrap" twice. You can only use an id once per page. I’m sure you already know that though ;P
I’m also wondering why you chose to break your CSS up into so many serparate files? I realize each has it’s own distinct place/styleset for the page, but each is so short, it seems it would be easier to contain all into one file and just properly comment where in the file the section is located.
But overall, I really like it! This is one of a best designs I think I’ve seen recently.