Adjusting CSS for Accessibility

Ok, I've come to realize that my CSS is not the most accessible piece on the block. My main problems are: the sizes are too big for resolutions under 1600x1200 (and that's what I run, and for a while I was like what, it works fine, then I checked it with 1024x768...yeah wow), IE garbles it, and maybe a case of divitis.

Here is a link to my main css (http://www.greenbomber.com/style/gb.css).

Also, if you want to test the CSS on a page I have a test page set up (kind of like the W3C) here (http://www.greenbomber.com/test.php?style=gb.css).
Be sure to copy your CSS down as when you create a new one, it deletes the old one.

Thanks so much in advance for helping me.

Set text size for the body at about 0.89em.

That will give you a reasonable text size across most resolutions, and still allow the user to change it.

If it's font sizing you want try Owen Briggs' sane css sizes sane css sizes (http://www.thenoodleincident.com/tutorials/typography/index.html)

...or was it more the layout you were unhappy with?