running postgresql as a linux service

Hello, I have succesfuly installed PostgreSQL 7.4.1, on my OS which is Red Hat Linux 9.0.

I start the server with:
$ pg_ctl -D /usr/local/pgsql/data -l logfile start

And stop it with:
$ pg_ctl -D /usr/local/pgsql/data stop -m fast

There are two questions here, which I want to put to you guys:
1. How can make PostgreSQL run as a Linux service so database server starts at each reboot
2. How can I register the PGDATA environment variable, so I don't have to use -D /usr/local/pgsql/data parameter (and don't use -l logfile if it is posible) when run the start command

Thanks, Raul Secan.