Some install questions PGDATA and postgresql init script

NOTE: I posted this in novices also, but I have not seen it posted so I
thought I'd put it up here too.

I've had pgsql working in the past, but can't get it working now.
In order to get this thing working, there are a few basic things I don't

fully understand.
I'm running an 7.0.2 RMP on RH6.2. I purchased the CD's from Postgresql

(basically to give some support to the developers).

Question(s)

I create a dir and do a initdb it does fill the dir with the appropriate

file structure.

I don't get the initscript /rc.d/init.d/postgresql.

If I leave it as is (which I believe I should) it does start postmaster.

Should I set the PGVARS (e.g PGDATA) in that file before it gets
started?

What's with these lines?

if [ -f /var/lib/pgsql/PG_VERSION ] && [ -d
/var/lib/pgsql/base/template1 ]
then
export PGDATA=/var/lib/pgsql
else
export PGDATA=/var/lib/pgsql/data
fi

Shouldn't I be looking at PG_VERSION in my newly created dir? and why
the export of PGDATA Isn't my PGDATA supposed to point at my newly
created database or is it the file system.

Going on with that last topic. If initdb creates a database "system"
and createdb creates a datbase in that system, exactly where is my
PGDATA supposed to point at the system, the database, or
mysystem/base/template1 ??

Lastly, PGPORT does it matter? 8080 8081 5432, as long as I stay
consistant. 80 if I want to do httpd

Oh one more thing. I saw a note posted by someone that said the
readme.linux or linux.readme is very helpful. I can't find that file on

the CD can anyone send it to me or if you know it's on the CD, tell me
where it is. Maybe I have to unzip something to find it.

Thanks in advance