i always learned it that the .pfm files are the metrics -- the hinting, kern tables, etc. -- that tells the font how to assemble characters in relation to each other. the .pfb are the outlines, which tell the programs (that can read PS fonts) how to display them on the screen and how to them print them.
in previous versions of windows, you had to have ATM installed on your machine. XP has support for PS fonts natively so you don't need that. you may, however, need admin rights to install them.
so yes, dump all that into the font folder. .afm files:
You can safely eliminate the .afm files, those are from back in the days when people used to load fonts onto the hard drives of imagesetters. Say at pre-press places that were using Postscript fonts with non-desktop publishing systems.
"Lucy, you got some 'splainin' to do!" - Ricky Ricardo