PostsSQL 6.5.2-2 Linux RPM Installaion

Hi
This is my first attempt to install PostgreSQL in a PC running Redhat 6.0.
The following RPMs were installed OK.

postgresql-6.5.1-2.i386.rpm
postgresql-server-6.5.1-2.i386.rpm

I assumed the above RPMs are all there needed to start the PostgreSQL
backend server for a test run. Upon rebooting the system, linux reported the
path of PGDATA path /var/lib/pgsql/base/template1/pg_class not found.

Am I correct that the RPMs do not install the data and library in the
Default directories as those in the Admin Guide. Is there is documented
reference on the changes on data and library locations using the RPMs, and
how do I fix the changes to start using Postgres?

Thanks.
Samantha Sun
Fisheries
Dept of Primary Industries
Tel.: 61-7-32248580