You would have to cite the website rather than the teacher specficially as most of us use a "handle" or "username".
Da Vinci World. 2007. National Society for Leonardo Da Vinci. 14 Feb 2009
Annotation about this source.
“Golden Palace.” 10 November 2005. http://www.goldenpalace.com/welcome.php
The works cited page will be indented 5-7 spaces. If you know the name of the article, put it in quotation marks as well as the date it was downloaded by you in your search. Always include the url or web address in your works cited page. I have given you two examples from the links below.