Under the featured content slider "Headline/Action text" add the following attribute, between square brackets [], where you'd like the icon to be displayed:
icon:icon-name-goes-here/icon
Don't forget to add the square brackets "[]"
Go to fontawesome.com and search for the icon of your choice. (Only free font awesome icons are available for use unless you have a pro account)
Click the name of the icon to copy it and paste it in place of "icon-name-goes-here". Keep "/icon".