Hi try taking out the "/mysite" and "style.css"
basically with relative links you need to think where your html sits.
In this case in the mysite folder. If you added a new folder in my site called "css" you would link the css "css/style.css"

If you are ever in doubt what you can do to guarantee linking it an absolute link. for example <link href= "www.mountaineerevents.com/mysite/style.css" type="text/css" media="screen" />

google relative links vs absolute links to find more tricks and tips.