I learned a lot while reading High performance web sites by Steve Sounders.
It is a relatively thin book, 137 pages, with quite many diagrams and screen-shots. It also repeats and repeats the main ideas. So the book is a fast read.
I liked the fact that the whole book can be summarized by listing the 14 rules that it defines and explains. I also liked the fact that the rules are not only there to follow blindly (although, you could, most probably, follow them blindly and get away with it successfully), but are explained, reasoned and the benefit of following them is demonstrated using popular US web sites. I also liked the metering tools and demonstration tools that the author uses.
I think that you can learn quite a lot from the author beyond the book itself, so check out his web site at http://stevesouders.com/, where he has a blog and other interesting resources (e.g., videos).
The author also had an article based on the book on CACM, see the author's blog post about this, along with links to the publication.
Read reviews about the book on Amazon. Most of them are very informative.
A good read -- I think that you can find most of the information if not all on the web and in the papers and talks that result from the book. Still, the book itself is nice to have around.
