This instructions are valid if you are using jabberd14 as the main server. If
you are going to use jabberd2 you must edit /etc/confd/jabberd and change 
jabberd14 to jabberd2.

This is a small help to get you started with Jabber in Gentoo.
Edit /etc/jabber/multiple.xml . This is the main jabber server config file.
There change all references to localhost with the FQDN (Fully Qualified Domain 
Name) for your server.
If you are going to use SSL you must change the line:
 <ssl port="5223"/> <!-- 10.1.2.3</ssl> -->
To:
<ssl port="5223">10.1.2.3</ssl>
Where 10.1.2.3 is your machines IP (not name, IP here).
Also, edit:
<ssl>
      <key ip="10.1.2.3">/etc/jabber/gentoo.pem</key>
</ssl>

at the end of the file to your IP.

You can now test your setup with the command:
jabberd -c /etc/jabber/multiple.xml -D

And try to connect to your new server with a jabber client. If all goes well
kill your jabber server (control-c) and if you have installed transports go
configure them now.