Select the Home tab. Click the tiny arrow to the right of the word Paragraph (top center) in order to open the Paragraph dialog box.
In the Paragraph dialog box under Line spacing (near the middle of the dialog box) select Double. Set the Spacing After to 0 pt. Check the box Don't add space between paragraphs of the same style.
Click OK
The entire paper should be double-spaced including the Works Cited page.