Google Fonts - Making the web more beautiful, fast, and open through great typography
IconStore - Free icon packs by first-class designers
Font Awesome - Font Awesome makes it easy to add vector icons and social logos to your website. And version 5 is redesigned and built from the ground up!
Feather Icons - Simply beautiful open source icons
Glyphy - Copy & paste fancy fonts + cool symbols ☞✺✐™
Noun Project for Mac - Search nearly a million icons. Now in color!