Greg Linden links to a heavily lesson ladened LISA 2007 paper titled On Designing and Deploying Internet-Scale Services by James Hamilton of the Windows Live Services Platform group. I know people crave nitty-gritty details, but this isn't a how to configure a web server article. It hitches you to a rocket and zooms you up to 50,000 feet so you can take a look at best web operations practices from a broad, yet practical perspective. The author and his team of contributors obviously have a lot of in the trenches experience. Many non-obvious topics are covered. And there's a lot to learn from.

The paper has too many details to cover here, but the big sections are:

From FRESH Ports and their website:

ISPman is an ISP management software written in perl, using an LDAP
backend to manage virtual hosts for an ISP. It can be used to manage,
DNS, virtual hosts for apache config, postfix configuration, cyrus
mail boxes, proftpd etc.