The server is started already but how do you know if it is really working and there were no problems. Have a look in the logs/ directory. There should be a few files in there:
$ ls -l logs/ total 40K -rw-r--r-- 1 20K 2009-02-03 21:48 tigase-console.log -rw-r--r-- 1 16K 2009-02-03 21:48 tigase.log.0 -rw-r--r-- 1 0 2009-02-03 21:48 tigase.log.0.lck -rw-r--r-- 1 6 2009-02-03 21:48 tigase.pid
2 first files are the most interesting for us: tigase-console.log and tigase.log.0. The first one contains very limited information and only the most important entries. Have a look inside and check if there are any WARNING or SEVERE entries. If not everything should be fine.
Now you can connect with a Jabber (XMPP) client of your choice. The first thing to do would be registering the first account - the admin account from your init.properties file: admin@jabber.your-great.net. Refer to your client documentation how to register a new account.