It's difficult to say what 'looks good' on a web page. There's no shortage of CSS tutorials, kits, and, of course, examples - but how does one actually construct one? This is my first real website, and I'm not exactly 'mature' (lol).
I'm a fan of the white background. It's a damn sight cleaner visually speaking, and hence a lot easier to read. The orange colour scheme originates in Seth Godin's blog, which is currently 9th in the Google search for "blog". :drops jaw: It's both lively and quite warm, IMHO.
And my much loved clean white colour complements it nicely - the slightly shaded in side panel (#FAFAFA) makes sure you remain interested in the primary material, as you don't get so easily distracted by another empty white space. The eye seems to gravitate towards white space.
An accompanying design-related observation is that large line-spacing is essential for good readability. Admittedly, my site is currently still very much in development - but I think (read: hope) you'll find it easy on the eye! The large grey space won't be such an issue in weeks to come, since, after adding the commenting facility to this blog/journal, I will definitely be creating an automated side-bar which fills with appropriate links and information. That hideous breadcrumb which is to be found at the top right if you visit an article (such as this one) will probably be moved over there too; I do think it's best to have one somewhere though, since the ability to jump by category is often very useful. I do wonder if Wikipedia would benefit from a breadcrumb which tracks your history of visited pages.
I've switched from Georgia to the general sans-serif font. Everybody else uses it, so it appeals to the viewer's sense of continuity, and, of course, it's highly readable. I have heard it said that Georgia is highly readable on the screen, and will readily agree too - except where mathematics, equations and symbols are concerned.
My page on Euler's Identity looked horrific with Georgia, and all those little serifs. And trying to following the hierarchy of brackets just gave you headaches. Admittedly, they're still not classic examples of clarity, but they're better - trust me. I'll eventually install LaTeX, but that's still just another good intention. It's a remarkably good project, though, it must be said.
Anyway, everything's still evolving. Next generation: comments.