how to install tomcat 6 and setup it and make it work after setup

hi,
I'm using centos 5.0 and installed java development .
now I'm tring to install apache tomcat 6 core to be trained in jsp
when I try I get the following

[root@localhost ~]# /opt/tomcat6/bin/startup.sh
Using CATALINA_BASE:   /opt/tomcat6
Using CATALINA_HOME:   /opt/tomcat6
Using CATALINA_TMPDIR: /opt/tomcat6/temp
Using JRE_HOME:       /usr
[root@localhost ~]#

and when I try
 http://localhost:8080/
after that I get

Unable to connect
Firefox can't establish a connection to the server at localhost:8080.
    *   The site could be temporarily unavailable or too busy. Try again in a few
          moments.
    *   If you are unable to load any pages, check your computer's network
          connection.
    *   If your computer or network is protected by a firewall or proxy, make sure
          that Firefox is permitted to access the Web.

please help to get it work for at least the samples applications
best regards
hatem gamal