Get Start YSlow
1. What's YSlow
YSlow is very nice Web Development Tool to help your web sites performance, it's add-on to your browser, once you installed, it would like following image, analize your page, telling you what's you need to do to improve your pages' performance.
YSlow created by Yahoo, they added serval rules to check your website.
2. How to use it?
Very Simple, click the Run Test Button