Steve Souder’s new book, High Performance Web Sites, is excellent.

Souder has worked at Yahoo since 2000. His current title is Chief Performance Yahoo!.

Steve’s job is making Yahoo pages load quickly.

His book lays out 17 fast-and-easy techniques to speed up your site.

Except for Tip #2 (Use A CDN), these tips are essentially no cost.

Really.

Like many, I’d always thought the bottleneck for most large sites was database access. So speeding up a site meant more indexes (read: buy more disk), faster processors (read: upgrade your servers), and more database-savvy apps (read: costly refactoring).

While these three can bottleneck your performance, Souder describes how front end design choices can slow down or speed up a site by 10 to 20%.

Simple little things. Expires headers. CSS sprites. Gzipping. Smarter DNS. Amazing that little things can matter so much.

Are your IT folks already doing all this? Probably not. Souder grades the web’s biggest sites and finds that even among online leaders these best practices are used inconsistently. Sure, Google and CraigsList are really fast, but they also send really lean pages. Yahoo is a more interesting case: it sends really fat pages (images, content, code), but their pages load fast regardless.

If you’re not a tech person: Souder’s 17 tips are mostly server and page configuration options. There’s IT effort to do them, but typically not much.

(It is as if some credible person let you in on the secret that — I’m making this up — “salespeople with their phone numbers above their name on their business card on average sell 10% more each month than salespeople with their phone number below their name.” And they were right.)

Here are the book’s chapters:

• Chapter 1: The Importance of Frontend Performance
• Chapter 2: HTTP Overview
• Chapter 3: Rule 1: Make Fewer HTTP Requests
• Chapter 4: Rule 2: Use a Content Delivery Network
• Chapter 5: Rule 3: Add an Expires Header
• Chapter 6: Rule 4: Gzip Components
• Chapter 7: Rule 5: Put Stylesheets at the Top
• Chapter 8: Rule 6: Put Scripts at the Bottom
• Chapter 9: Rule 7: Avoid CSS Expressions
• Chapter 10: Rule 8: Make JavaScript and CSS External
• Chapter 11: Rule 9: Reduce DNS Lookups
• Chapter 12: Rule 10: Minify JavaScript
• Chapter 13: Rule 11: Avoid Redirects
• Chapter 14: Rule 12: Remove Duplicate Scripts
• Chapter 15: Rule 13: Configure ETags
• Chapter 16: Rule 14: Make Ajax Cacheable
• Chapter 17: Deconstructing 10 Top Sites

You can read most of the book for free on O’Rielly’s table-of-contents page (mouse-over and click the sections on that page to expand), but don’t. Buy it instead. $20 at amazon, $30 at orielly.

Heck, buy two copies for your IT team. The purchase will be your highest percentage ROI decision this year, book cost + IT implementation cost versus increased sales from faster more usable site.

Speed is an often-overlooked component of web site usability.

All other things equal, faster sites sell more.

Buy this book.