The layout is friendly, that's great
First up: I luv the "HTML Invalid" button
Classic. I hate the "Bush in 2004" button, cause he's a F$*@#())(#@*%(#)* )#(# )%(@)!_$%(*@ $(!!.
The navigation, however, could use some work.
For example, how do I know that I'm on the home page? There is nothing telling me where I am. By adding an id to the <li> of the current page, you can style that differently so that it is obvious as to where the user is.
OUCH! Just checked your code, and your menu is a pile of nested <div>'s... Totally unnessacary, and semantically meaningless
You could quite easily use an unordered list for the menu and set the bottom border of the current pages menu option to a different colour to signify where on the site the user is.
Instead of the standard blue for links, how about a slightly softer blue...like #4B73AA, with maybe a lighter blue, like #6F91C4 for the visited links.
and maybe orange for links hover for a bit of contrast?
I could keep going, but I think that's enough for now