question

A question for all you smart and creative LJ users:

I've noticed that some of you have customized mood icons. Where do you find these lovely commodities? I've run across a few sets in icon communities before, but not many and they're difficult to find. Also, once you find a set you like, how do you install it?

Thanks to whoever can fill in this intrigued but bewildered, non-techie LJ user (who cannot control her excessive use of adjectives.)