Philip Greenspun runs a successful web consultancy with several very busy sites, and seems to have tried to distill all that he has learned into one book. A lot of what he says is very wise, and although I disagree with some of his technology choices, he has thought everything through in great detail. There are quite a few sections which I will re-read and study for my own projects, but many others I will never bother with again. The book's main drawback is its size, which makes it hard to cherry-pick just the bits you need.
If you are looking for ways to use the latest technology to make a web site look cool, this is not the book for you. If you are building or running a site or business with lots of users, and you want to keep them and avoid going crazy in the process, you need this book. And the photos really are good.