[gruseom]

The definitive treatment of every item on that list, and more, is Steve Souders' book (http://www.amazon.com/High-Performance-Web-Sites-Essential/d...) Get it immediately and do what he says. In my experience, the differences are very material.

The one thing I would add is: wherever possible, give resources immutable URLs (that is, when a resource changes, change its URL) and tell the browser to cache them not for an hour but forever. This saves endless wailing and gnashing of teeth on both sides of the browser-cache abyss (i.e. things not being cached when you want them to and -- much worse -- things being cached when you don't want them to). Seriously, this rule changes misery to joy.

p.s. While copying the above link I noticed that Souders published a sequel (Even Faster Web Sites). Who here has read it? Can you report how good it is?

[dunkjmcd]

Even Faster is mostly JavaScript and image optimisations. Not quite the holy Grail of the first book but a good one to have in your collection none the less.