localhost:8080 i can't use it

By default, the web server isn't listening on port 8080 -- just on port 80.
If you want it to listen on port 8080, you'll need to edit /etc/httpd/httpd.conf and restart Apache. This is fiddly. If you want to get at port 8080 from a different computer, you'll also have to disable your Firewall or add a service to it.

Why do you want to use 8080 instead of the default 80?

I'm afraid I've never done an install of Tomcat, although it's been on my "I should play with this sometime" list for a while.

A question: Is the Tomcat installation meant to contain its own web server, or do you intend to use it as part of the built-in Apache web server?

In order for Safari to be able to open http://localhost:8080/, some program (presumably a web server of some sort) needs to be listening on port 8080. The built-in Apache server by default listens only on port 80, the default HTTP port. The fact that opening http://localhost gets you the Apache "successful install" page indicates that the built-in Apache server is operating as expected; the fact that opening http://localhost:8080/ gets you the error indicates that no program is listening on port 8080.

Port 8080 is usually used when the person setting up a web server does not have administrative privileges on a machine, and so cannot configure the web server to run as root. Ports below 1024 may only be opened by root on a UNIX system, so the default http port, port 80, is off-limits to such a user.

Presumably, you have admin privileges on your PowerBook, so if you wanted, you could make Apache interface to Tomcat (or replace Apache with your preferred server front-end to Tomcat). Hence my question...