Purdue OWL - The Purdue OWL is an excellent resource for writing.
Purdue OWL Guide to Citing an Article on a Website using MLA Format - Use this resource to help you use MLA formatting for an article on a website. Also, if you ever need to cite a tweet, the information for that is on this page also!
Purdue OWL Periodical Citation Guide using MLA Format - This link has the information you need in order to use MLA format for newspapers and magazines.
Thesis Writing Explanation - The Owl at Purdue's thesis writing information.