Webmaster Level: Beginner to Intermediate

...k, i, s, s, i, n, g! Perhaps you heard our announcement that speed is a signal in rankings, but didn’t know where to start. We’d like to help foster a lasting relationship between you and a responsive experience for your users. Last week I filmed my updated presentation from "The Need For Speed: Google Says It Matters" which includes three first steps to understanding site performance. So grab headphones and some popcorn, then verify ownership of your website and download a plugin, and we’ll all be comfy with site performance in no time.

Just curious about the Q&A? No problem! Here you go:

Is it possible to check my server response time from different areas around the world?
Yes. WebPagetest.org can test performance from the United States (both East and West Coast—go West Coast! :), United Kingdom, China, and New Zealand.
What's a good response time to aim for?
First, if your competition is fast, they may provide a better user experience than your site for your same audience. In that case, you may want to make your site better, stronger, faster...

Otherwise, studies by Akamai claim 2 seconds as the threshold for ecommerce site "acceptability." Just as an FYI, at Google we aim for under a half-second.
Does progressive rendering help users?
Definitely! Progressive rendering is when a browser can display content as it’s available incrementally rather than waiting for all the content to display at once. This provides users faster visual feedback and helps them feel more in control. Bing experimented with progressive rendering by sending users their visual header (like the logo and searchbox) quickly, then the results/ads once they were available. Bing found a 0.7% increase in satisfaction with progressive rendering. They commented that this improvement compared with full feature rollout.

How can you implement progressive rendering techniques on your site? Put stylesheets at the top of the page. This allows a browser to start displaying content ASAP.

Page speed plugin, videos, articles, and help forum are all found at code.google.com/speed/.