Centering "tables" and columns with css

[RedCherry]

Anyone know how to center a "table" of two columns using CSS? When I redesigned theredcherry, all the category pages are tableless and optimized for 1024 resolution. But in the bigger resolutions, it is all crammed to the left.

I used this:

/* ---  LEFT SIDE BAR --- */
#menu {float: left; padding-left: 10px; padding-right: 10px; text-align: left; width: 200px}

/* ---  MAIN PAGE CONTENT --- */
#content {width: 770px;   float: left;   text-align: left;   margin-left: 5px;   margin-bottom: 0px;   padding-bottom: 0px;   padding-left: 5px;}

I tried putting a big <div align="center"></div> around the whole thing, but that didn't work. When I tried different floats, they overlapped, lol. And % widths also didn't seem to work.

This is the first big project I did almost completely tableless, so I'm still learning.