I do it pretty much the same way Kristi does....I have all of Al Ward's stuff in a folder, and so forth. I also have a print out of each brush in the file in a 3 ring so that I have them catalogued.....since the file names are so much help.  I also do the same thing for actions, textures and anything else I DL for PS or PSE. So far, it has worked pretty well.....My main problem is that I'm as overloaded on "stuff" for PS and PSE as I am on digi-downloads! What to do! I've already filled up an external HD and am working on a second.