MLA Style:
https://owl.english.purdue.edu/
Purdue OWL YouTube vidcasts:
https://www.youtube.com/playlist?list=PL4917D9E21FA6EDFF&feature=plcp
Rhetoric:
americanrhetoric.com
AP Language
https://apstudent.collegeboard.org/home
http://apcentral.collegeboard.com/home