You can put commands you want to run in the last script run by Red Hat, the /etc/rc.d/rc.local file. Just add the commands you want to run to the bottom of the file.
You probably weren't switching to the full root account.
To change to the full root account (system administrator), open an x terminal and use these commands from your user account. Note the change in the prompt.
[fancy@tinwhistle fancy]$ su -
If you will edit your profile and put your distro in it, it will save having to re-read earlier posts. Look to the left of this post for an example.