I'm following the instruction in Google's Material Icons Guide but for some reason it does not work when I tested it in JSFiddle. The icon/image of a face do not show up.
<link href="https://fonts.googleapis.com/icon?family=Material+Icons"
rel="stylesheet">
<i class="material-icons md-48"></i>
you just need to include the link to the font and then use it:
<link href="https://fonts.googleapis.com/icon?family=Material+Icons"
rel="stylesheet">
<i class="material-icons">face</i>
working JSFiddle example