[olug] Postgresql Install

[edcarlsen at cox.net]

I have a Mandrake 9.1 system and installed Postgresql for eventual interface to Apache2 through PHP.
I am trying to build a database but I am confused. The instructions talk about a database cluster. I only know clusters as hardware clusters.
I have postmaster running and trying to create a database. Do I need to run the initdb command or the createdb command?
And, it wants me to set the PGDATA environment variable. Is this done in the /etc/profile?
Sorry for dumb questions, but I tried reading the docs.
Thanks.