CSS - Swiched To Css...finally...need Some Help

I just made the switch...well, sort of. I have been using a bit of css
here and there, but I have attempted to build a recent client's site
using all css. I've studied some pages and broken them apart, I am
getting it...again, sort of...and I now have a dozen reference sites
listed in my bookmarks.

So, to the question.

I have posted the index page...I was pretty psyched to get even this
far. It looks good in everything but ie...which is what I need it to
serve most...unfortunately these client's aren't too web sophisticated.

I'm not sure where I went wrong...and I am sure my organization is far
from clean, but again, it's the first one.

Could someone please help me out on this one? And/or give me any tips
on how to make this better?

www.rookscommunications.com/projects/inrs/index.html