Before i begin i must say that if this is your first website, its pretty darn impressive. My first website was horrible compared to this.
tips for improvement...
change your typography, the fonts hardly fit your design
Don't use the curved corners + gradients look unless you're very experienced in web design. They don't look professional when not implemented right.
Make your site degrade gracefully in older browsers. with css turned off the site becomes a mess.
things i really like...
The javascript-free drop-down menu is very impressive. First time ive ever seen one.
Cool header image
Keep up the good work!