Investigating design tools for my blogs, I stumbled across Firdamatic, which bills itself as "The Design Tool for the Uninspired Webloggers". This is a clever online form that will generate all of the CSS required for a 2-column or 3-column layout. It requires you to choose the colors you want for the various elements of your blog (font colors, background color, link color, etc.), so you might want to employ a color schemeer as well.
Color Scheme Generators
I have been playing with a couple of these online tools which say they'll generate a color scheme for your web page or blog. These are a couple of the tools which I like. Several of them even have a version which can be downloaded for use when you're not connected to the Internet.