A Year Without Rain is a nice font style designed to quickly give an original handwritten effect to your text projects.
To install a font unzip the files you have downloaded, then put the font files (.ttf, .otf) into /Library/Fonts . A Year Without Rain font integrates quickly into your system and you can easily access the custom glyphs though any text editing application.
Mac OS X comes with pre installed font style and A Year Without Rain will simply be added to your pre existent library. The process is managed through the Font Book application, where you can easily browse and preview your currently installed fonts.
To learn more about dealing with the Font Book application you can easily access the Apple support page HERE.
NOTE: A Year Without Rain font is free for personal use only. For commercial use a license must be purchased and you can find details in the included Read Me file.