Boot and Init files

[Wilczek, Scott]

I come from a DOS evironment and am used to having all my system
configuration in one place (AUTOEXEC.BAT and CONFIG.SYS).  Is there a
document or URL that explains how and what files the Linux boot process
uses??

I've been trying to setup up IP forwarding using ipchains.  I need to know
where to put my ipchains commands so that IP forwarding is enabled for all
user on the Linux box.

I'm using Red Hat 6.1.

Thanks,
STW