Table layouts are ten years obsolete. If you Google for two-column CSS layouts, you'll find a blue million of them, templates, tutorials, the works. Pick one that suits you and deconstruct it to see how it works. Here's a good place to start.
I saw this new CSS3 feature in the book HTML5 and CSS3 for the real world...should work for you.
Unfortunately, CSS3 is still a work in progress, and support for its features is patchy in newer browsers and non-existent in older browsers. Those browsers that do support multi-column layouts mostly require vendor pre-fixes to make it work.