If I have a book that has several essays by several authors, how can I cite it inside the text and in the Work cited page?
A book of essays by different authors is called an anthology. You're probably using an MLA reference guide, which should lay out the exact format for the works cited page's entry (remember that you must follow the example they show exactly in terms of spacing and punctuation)-- you're looking for the heading that the guide will describe as something like "A Work in an Anthology." Below, I've pasted a link to a citation generator, which will do the work for you, and to a good online handout on MLA style.
The works cited entry will begin with the last name of the author who wrote the selection in the anthology; your in-text citation should have the last name of the author, then a space, then the page number of whatever you're citing from the anthology, all enclosed in parentheses, like this: (Stone 42).