I would tell you to read the docs, but I couldn't find that in the docs. I couldn't even find a wiki page on it. But then maybe I don't know the proper keywords for a search (tried SSL and HTTPS to n avail).
JBoss in Action, section 6.4, provides detailed steps.
i was able to to do my job. i created a .certificate file using java keytool utility and put it in /server/default/conf directory and renamed it chap8.keystore.
than uncomment some stuff in /server/default/deploy/jbossweb.sar/server.xml: