Just put the font files in your c:\windows\fonts folder (assuming your windows folder is "windows" and your system installed on C drive)
Make sure the fonts are free before you post them anywhere, you don't want to get banned from anywhere for posting illegal fonts.
As InFlames said, once you drag the font files into your fonts folder (which is in the control panel), they will be installed and automatically be accessible from the font dropdown in Photoshop.
What font type you want to install if it truetype (*.ttf) you do as InFlames said if it opentype (*.otf) you copy to C:\Program Files\Common Files\Adobe\Fonts
Also make sure that you do not install too many fonts at the same time, otherwise they seriously eat up your system resources. Keep them around 500 at max.
be sure to restart photoshop after adding fonts to the fonts directory. Took me a bit to figure out why i wasnt seeing them at first.