MLA uses parenthetical citations for in text references. Whenever you use a quotation or paraphrase, you'll want to include your citation in parenthesis at the end of the sentence, just before the period. For books, it's important to include the author and page number in these in-text citations. For an example, look below:
Friere argues that the banking method of education, where the teacher deposits information in the students' mind, is not conducive to cultivating critical consciousness (72).
In the example above, I included the author's name in the sentence, so I don't need it in my citation. Therefore, my citation is simply the page number where I found the concept I'm paraphrasing.
For web sources, or sources without a given author, you would use the first title that appears in your works cited entry for the item -- that could be the title of the article, the name of the website, or film, etc. You would not need to worry about including a page or paragraph number for a website.