First thing's first:

Download YSlow for Firebug if you haven't already, then skim over Yahoo!'s article about the thirteen best practices for speeding up your website:

1. Minimize HTTP Requests - (Don't make me download a lot of crap.)
2. Use a Content Delivery Network (Have someone else serve your shit.)
3. Add an Expires or Cache-Control Header (Stale bread is best for french toast. Really.)
4. GZip Components (Zip it up!)
5. Put Stylesheets at the Top (I need to see your site before I click on stuff, dumbass.)
6. Put Scripts at the Bottom (See above.)
7. Avoid CSS Expressions (Who uses them anyway?)
8. Make Javascript and CSS External (Duh.)
9. Reduce DNS Lookups (Don't be a social media slut.)
10. Minify Javascript and CSS (Nobody wants to see your whitespace.)
11. Avoid Redirects (I came to your site, not theirs.)
12. Remove Duplicate Scripts (Duh.)
13. Configure ETags (Yeah, I didn't know what these were either.)

I also recommend setting up WP Super Cache after all is said and done. So here we go:

• The Unavoidables: Don't Make Me Download a Lot of Crap; or, Sometimes You Just Deserve an F From YSlow, You Shameless Self-Promoter
• Three Sexy Performance Rules for .htaccess on WordPress: Configure ETags, Gzip Compression, and Expires Headers
• Nobody Wants to See Your Whitespace: Minify CSS and Javascript using Yahoo!’s UI Compressor

* Full disclosure: Where do I stand? My front page gets a big fat B (88%) for making you download a lot of crap:

YSlow Score: DQuinn.net Home Page

YSlow gleefully reports that 32 CSS background images is downright sinful.

Before Jimbo attempted to address my question, he pointed out that I lacked all of the great tools I could be using that would enable me to easily answer my question myself. So I pass on Jimbo's wise recommendations to you!

HTML Validator. The validator installs a small, unobtrusive icon at the bottom of your Firefox status bar, indicating whether the site you're looking at is valid or not, how many errors have caused it to fail validation, and where in the source code the errors are located. Be sure to select the "SGML Parser" when you install the plugin. The validator checks markup against whatever DOCTYPE you specify, so it works for any flavor DOCTYPE—transitional or strict.

Web Developer Toolbar. After using this plugin, I find it hard to imagine what development was like without it. The Web Developer Toolbar provides a plethora of tools that allow you to test various aspects of your website before it goes live, right in Firefox. Here's a list of some of the things it can do:

• Allow you to see how your website performs
  • if javascript is disabled
  • if CSS is disabled
  • if images are disabled
  • when viewed at different resolutions
• Disable your cache, so you can preview your pages without having to worry about old edits popping up
• Outline or display various elements of a page (like headings, tables, links, depreciated elements, etc) that are not immediately (or normally) visible, so you can easily make sense of a site's structure upon first glance
• Analyze forms

On top of these features, the Web Developer Toolbar also has the ability to push your site to the w3c validator (for both HTML, CSS, and XML feeds), as well as push your site to accessibility validators to test compliance with Section 508 and WAI.

Firebug. Think of Firebug as the web developer's magnifying glass. Like the Firefox CSS Viewer, Firebug enables you to visually locate elements of your HTML code by mousing over those elements on the page. In a property window, Firebug lays out your page's hierarchy and shows you all the properties associated with each element in your page. What's more, Firebug allows you to actively edit a page that's on the web so you can preview what your changes would look like before you even implement those changes in your markup. Definite wow-factor for any web developer! But don't forget to implement the changes, of course, when they do pan out as you wanted.

FireFTP. Stop using a third-party client to upload your pages to the web! FireFTP, which integrates directly into Firefox, can do all the things your everyday FTP client can do without forcing you to leave your browser.

Sekmes! Geros kloties! And happy coding!