CSS Help needed - link included

Hi. I, like others, am trying to familiarize myself with CSS as I am learning that there are great benefits of using them.
But I think I'm creating a mess!

Please take a look:
http://multimediaelements.com/stuff/local2/home.html
Here are my issues:


Background image wont appear ( it was, up until I tried making the home.html page a template)
The nav buttons- on click they change padding or right margins - the lower line gets smaller, and the button labeled 'Best Pactices' shifts
The left side of the tab labeled HOME doesnt show up.
Last, but not least, when I tried to make this into a template, things got wacky...

First of all, your page comes up with 11 (somewhat minor) errors in the validator (http://validator.w3.org/check?uri=http%3A%2F%2Fmultimediaelements.com%2Fstuff%2Flocal2%2Fhome.html)

However, error #8 may have something to do with your background not showing up...

It's hard to be sure that a layout will work anyway, if it doesn't validate.

Dan

Thanks whizard for your reply and for pointing me to the validator.

Actually, the background image for the page is located in the stylesheet, which I got to show =)
I still generate 4 errors, but i dont think they are critical.

My problem still is this:
The left nav bar - when clicked, the btm line is sorter. It also appears to
display differently on IE6, than 7.0
left side of tab image not displaying

Remove this from your external stylesheet
<style type="text/css" media="all" type="text/css" rel="stylesheet" />
its causing your background not to show. Remove this one as well
</style>

Style tags do not go in external stylesheets.