How do I install my fonts on a Mac?

To activate a font, simply drag the font files into the Fonts folder, located inside the Library folder.
Macintosh HD > Library > Fonts (A short-cut to the Mactontosh HD is to press 'shift+cmd+C' in the finder.)

Or

You can use Font Book, free with Mac OSX, to install the fonts. More information can be found on the support section of the Apple website.

http://support.apple.com/kb/HT2509