Well.... Post what you've got so far and someone with better knowledge that I've got can have a look. I still run IE6 as well as FF for testing my own site, and yes, I find about a quarter of my visitors still use it. I've found most of my own launch problems were handled with a few tweaks here and there, usually to the CSS.

What template are you using for starters? Some have pretty speedy fixes as the authors of most of the common ones are here on a regular basis.