OSU's Writing Center Make an appointment or review their online help.
Many sites can guide you in using MLA. Especially helpful is Purdue's OWL site.
Take a practice quiz to learn more about how to and why we cite.
Check out these suggestions for determining if your journal article or book is scholarly.
Not all but many journal articles have a similar structure. Understanding this structure may facilitate your understanding, interpretation and analysis of the author(s)' writing. This web site details a common structure that authors use:
http://unilearning.uow.edu.au/reading/1d.html.