For an overview of the changes for MLA 8, see this page from Purdue OWL: MLA Eighth Edition: What's New and Different.
Core Elements of an MLA Citation
As outlined in the 8th Edition of the MLA Handbook, there are nine core elements of an MLA citation:
The core elements of any entry in the works-cited list are given below in the order in which they should appear. An element should be omitted from the entry if it's not relevant to the work being documented. Each element is followed by the punctuation mark shown unless it is the final element, which should end with a period.
Some sources will have more than one container, and these should be included in your citation. For example, a journal article accessed in a database has the primary container of the journal in which is was published, and the secondary container of the database in which it was accessed. Similarly, a television episode accessed on Hulu carries the television series as the primary container, and Hulu as the secondary container.
For further explanation of core elements and containers, and examples of how they work, see Works Cited: A Quick Guide, from the MLA Style Center.
Online sites specifically for MLA.