If you know CSS well, there's no need for it. It's just a style sheet by one designer and if you are a web designer yourself, then you should be able to create a style sheet yourself and know about common browser issues.
The problem with pre-defined style sheets, regardless of whether it's one of the boilerplate stylesheets, Eric Meyer's CSS reset, or this one, is that they're all designed to include every possible scenario that may or may not be relevant to the site you're designing, something you will never need for a single site. So, I'd say use the documentation in these style sheets to learn whatever you have not caught up with yet, and adapt whatever you feel is needed. I recommend against using these style sheets as a base, however, and utilize it as a reference instead.