If you’re a recent switcher, you’re probably used to dragging and dropping fonts into a folder in Windows in order to install them. As with many other aspects of OS X, installing fonts is even easier on your Mac.
In fact, it really couldn’t be easier. Download the font you want to install, and double-click it. The Font Book will open. Click the Install Font button.
The Font Book will now display your newly installed font.
And now any time you want to use that font, it will be available in your list of fonts.