I think the problem with the background is that it's messy. You could go with a solid color. Textures are very popular right now and could go well with your design for a clean look. The 'about | team | philosophy' stuff really belongs at the bottom.
As far as login/register. I'd put a login panel (username/password) with a sign-up button on it. Don't make people go to another page to do that.
Congrats, great work. Out of curiousity, how long did you spend learning?