New Installation

Hello,

I am about to begin my first installation of PostgreSQL. :-)  At the
moment I am installing Red Hat Linux ES v3 on a brand new machine for
use as a database server.    The machine has two RAID arrays.  The first
is an 18GB RAID 0 array that I intend to use as the system drive (/boot,
/, swap space, etc.) while the second is a 140GB RAID 5 array that I
plan to utilize for the database.  I am at the point where I need to
partition the arrays.  What considerations do I need to keep in mind?
Where does the PostgreSQL software get installed?  Where are the log
files kept?  What directory does the database end up in?  Are indexes,
procedures, tables, etc stored in separate locations?  Should they be
for performance reasons?  What can I do now while installing the OS and
eventually PostgreSQL to avoid problems and improve performance in the
future?  TIA for helping out a newbie.

Kind Regards,
Keith