Debian equivalent of rc.firewall??

[Stefan Srdic <linuxbox@telusplanet.net>]

I've just recently switched distros from Mandrake to Debain, I started 
out with Mandrake because I wanted to learn some fundementals before 
expanding to a "true" Linux distribution.

I'm having troubles setting up IP Masquerading. When I used in Mandrake 
(Red Hat based) I wrote a script (rc.masq) and executed it a boot-time 
through the rc.local configuration script.

Now, in Debain, I'm having trouble in finding out which rc*.d directory 
I should insert my script and what to name it. I read through the IP 
Masq HOW-TO but it seems to be RedHat biased.

Where would I insert my Masq/Firewall scripts and how would I get them 
to be read at boot-time?

Thanks

Stef