Couple quick points:
Remember to declare fonts for all of your text. On the home page, the About text, sidebar text and even the text in the footer hasn’t been declared and is just rolling back to browser defaults. You want to make sure you’re in full control in the way people view your sites!
Your sub-nav under "Home" "Sections" "About" is a little off. Under the "Sections" tab the sub-nav goes outside the bounding box you’ve set for it.