Advice on IE-specific style sheets/fixes?

I’m slowly finishining up my new site in WP. Main URL is michaelgaither.com/home.

All looks fine in Safari, Chrome, and Firefox. In IE (version 6 and 7, at least), there are an abundance of problems: The top navigation bar has wrong background color, random blog posts have centered text, and some of my sidebar icons/pics are missing page breaks.

Any advice on how to address this? Can I fix this in the main css style sheet?

Thanks,

– Michael