Image by adria.richards via Flickr

1. Login LockDown — adds extra security to WordPress by restricting the number of failed login attempts.

2. SexyBookmarks — sure, there are many ways to add lists of sharing icons and links to your posts — but this one is pretty.

3. wp-Typography — easily improve the typography on your site, em and en dashes, hyphenation, and much more.

4. WP Greet Box — give a simple little welcome message to visitors coming via various referrers, like Stumbleupon or Digg.

5. WP Minify — compress CSS and Javascript to speed up page loads. It can be a little tricky — I find I have to specifically exclude all 3rd-party scripts and stylesheets — but it’s highly effective.

• Rule 1 — Make Fewer HTTP Requests
• Rule 2 — Use a Content Delivery Network
• Rule 3 — Add an Expires Header
• Rule 4 — Gzip Components
• Rule 5 — Put CSS at the Top
• Rule 6 — Move Scripts to the Bottom
• Rule 7 — Avoid CSS Expressions
• Rule 8 — Make JavaScript and CSS External
• Rule 9 — Reduce DNS Lookups
• Rule 10 — Minify JavaScript
• Rule 11 — Avoid Redirects
• Rule 12 — Remove Duplicate Scripts
• Rule 13 — Turn Off ETags
• Rule 14 — Make AJAX Cacheable and Small

As he notes, fetching Web sites generally follows the “80–20″ principle: 20% of the time a user waits to see a page is spent getting the actual HTML page. 80% of the time is spent on everything else.

The book is still in the “rough cuts” stage, but sounds like an excellent and practical guide to making your site more usable and functional from a user perspective.