There's no doubt that your words, your posts, are the meat and potatoes of your blog or website. Those words, along with your lovely colors and pictures, tell your website's story. But, don't forget to pay attention to your font selections. The fonts you choose in designing your theme can influence whether or not people hang around to see more than a page or two of your pretty work.
In Playing With Fonts, the use of fonts within WordPress is explained, including how to find and change the fonts within a WordPress Theme, choosing fonts for your site, and how to set the styles for those fonts, including some great font resources and information.