Select the paragraph(s) you want to format
Go to the Home tab
In the Paragraph group, click the dialog launcher (small arrow in the bottom-right corner)
In the Indents and Spacing section, find the Indentation area
Set Left to the first-line position you want
Set Hanging to the amount you want the subsequent lines to be indented
Click OK
(Optional) Use the Ruler:
Drag the top triangle (first-line indent) to set the first line position
Drag the bottom triangle (hanging indent) to set the hanging indent position
(Optional) If using a style:
Right-click the style in the Styles gallery
Choose Modify
Click Format > Paragraph
Set Hanging indent and click OK