The site has good information about email ettiquette but seems to be a bit dated. The newest copyright on the site is 2011 but many of the pages list a much older date. After some digging I was able to find some references to social networking but the resource primarily focuses on email. I would encourage the author to redesign the site to address current technology.
The Nettiquette quiz requires java to run which will limit its use on mobile devices. In Google Chrome on Mac, the quiz was cut off on one side and difficult to read.