This isn't a huge long tutorial or anything like that it's just a simple site that you probably already know but I'm telling you anyways. www.dafont.com
This is one of the best sources for fonts that can be use in Photoshop or other programs.
Windows XP
Download the font--->Copy the font into your C:\WINDOWS\Fonts folder--->Enjoy!
Vista
Download the font--->Right click and click install font--->Enjoy!!!
Apple computers
Download the font--->Double click the font--->Click install font--->Enjoy!!!!