I found a not too high level explanation here:
http://www.gtlib.cc.gatech.edu/pub/linux/docs/HOWTO/other-formats/html_single/SSL-Certificates-HOWTO.html
Now what I'd really like to find next is a OpenSSL GUI for OS X.
Does anyone know of one?
I checked versiontracker, google, Apple, etc. without luck so far. I
hear there's one that comes with OS X Server.
Marc