A hanging indentation just refers to the lines in each citation (in your References list) after the first line. The first line will be left-aligned like normal, but each line after the first should be indented over 0.5 inches.
For example:
McCarter, S. (2009). Legal and extralegal factors affecting minority overrepresentation in Virginia's juvenile justice system: A mixed-method study. Child & Adolescent Social Work Journal, 3(26), 533-544.
The first line is normal and the second line is "indented" in. Each line after the first should be indented in like that.
The easiest way to do that in Microsoft Office is to right-click on the paragraph (in this case, this citation) and then left-click on Paragraph in the popup menu that shows up. On the Paragraph options screen, go down to Indentation and the drop-down menu under Special; then select Hanging.
This video shows another method for setting your hanging indention in Word.
