Whoa Whoa Whoa. Never ever log in and work as root. Just don't.
su to root when you need to, then go back to be mortal, it'll save you a lot of grief the first time you type rm -Rf and forget you're at root or in a dir with a link to root or some other god aweful mistake.
Now, on to postgres.
First, get 7.0.2 and build it from the tar ball, it is MUCH improved of 6.5.3, and will probably save you some heartache later on.
Now, follow the install instructions, which pretty much walk you through creating user accounts and databases. Here's the very short version:
Assuming you got through the part about creating the postgres user, installing and all that, you should hopefully have postgres running. Check with a 'ps ax|grep postmaster' command. If you see a line showing it running, you're set. If not, re-read the docs on starting postgres.
Once it's running, you need to su - postgres to be the postgres superuser. Next, createuser <username> will create users. createdb <dbname> will create dbs. If your username was gumby, you'd do this as postgres:
[PATH]$ createuser gumby
Enter user's postgres ID or RETURN to use unix user ID: 510 -> (Just hit enter here)
Is user "gumby" allowed to create databases (y/n) y
Is user "gumby" a superuser? (y/n) y
createuser: gumby was successfully added
[PATH]$ createdb gumby
now, exit out and become yourself again, and you should be able to connect with:
[PATH]$ psql gumby
and you're off!
