Below tutorial described how to check page speed of your blog/website.
Following steps tell you how to install & use Page Speed addOns.

Step-1: Install firebug add-on in firefox: https://addons.mozilla.org/en-US/firefox/addon/firebug/
Step-2: Install page speed : http://code.google.com/speed/page-speed/download.html
Note: Page Speed is a firebug extension. So you first need to install firebug.
Step-3: Open up the firebug console.

Step-4: Click on the “page speed” tab.

Step 5: Click ‘Analyze Performance’ button.

Result

you’ll get a score out of 100. The Best page speed website score as close to 100 as possible.