PC or MAC?

PC:
Method 1 - Start --> Control Panel --> Fonts,(in XP it makes it appear that you select a font, just "right-click" on the "fonts" icon in the menu and choose "Open") then click File --> Install New Fonts.

Method 2 - C:WINDOWS and drag font files on top of FONTS directory (Shift-Click on fonts if you are installing a few of them)

MAC:
Method 1 - Home --> Library --> Fonts and drag font files on it

PLEASE NOTE:
Photoshop MUST be closed when installing fonts or they will not appear in the font list. PS builds the font table when it is launched and any foints insatalled while open will not be added until next launch...

let me know if you have any trouble,
:)
retrocity