This is another excellent website (I've taken my examples from it):
Generally speaking, however, when you cite within your essay for a direct quote, you'll be using the following format:
(Author's Last Name Page #)
So, it would look like this: (Wordsworth 263)
Note how there is no punctuation contained within the citation. This is different than APA.
Additionally, the citation should be at the end of the sentence regardless of where the actually quote is, and it should be within the period. For example:
Romantic poetry is characterized by the "spontaneous overflow of powerful feelings" (Wordsworth 263).
If you use the author's name within your sentence, then there is no reason to embed it within the citation itself. For example:
Wordsworth stated that Romantic poetry was marked by a "spontaneous overflow of powerful feelings" (263).
Lastly, if you are using an idea that is not your own even if you are not using the exact words, you still must cite from where you got the idea. For example:
Wordsworth extensively explored the role of emotion in the creative process (263).
When it comes to giving credit, a general rule of thumb to follow is that if the ideas are not universal/general knowledge, then you must provide a citation. So, it is unnecessary to provide support when you make the statement that the Declaration of Independence was signed in 1776, but if you're discussing the feelings of the signers at the moment they were putting their signatures on the document, then you MUST give a citation as most people wouldn't be aware of how these founding fathers felt at the time.
This site is fantastic for MLA formatting. It's basically a template where you just substitute your information and it will make a proper MLA citation for you.
The sidebar on the right-hand side allows you to choose the resource style you use, including essay formats.
Hope this helped.