Here's little demo of including spritesheets from a Content Delivery Network.
(Copies of the spritesheets are also included in the local svg directory.)
- SVG is for everybody — talk by Chris Coyier
- Icon System with SVG Sprites — by css-tricks.com
- Styling SVG
<use>contents with CSS — by Sara Soueidan
- Font Awesome — free & open source
- Material Design Icons by Google — free & open source
- ionicons — free and open source
- The Noun Project — lots of high quality icon sets (permissive license, subscription required)
- fontello — icon fonts generator
- icon finder — various licenses, free and paid
- flaticon — login or subscription required
- fontastic.me — not maintained, lots of broken links ...