Home network with Debian

[JD Kitch <adahma@gmx.net>]

I've been running Debian Potato\Progeny for some time now, with a
single nic attached to cable modem.  I'm also running an ipchains
firewall.  I have added a second nic, which I would like to connect
the wife's windows machine to, and have my debian box do ip masq'ing
for the windows box.

I do already have the additional kernel module loading for the
second nic, and both are recognized.  Can anyone tell me how, or point
me to a reference on doing all this the Debian way?  I found a
pretty in depth howto based on Red Hat, but apparently the systems
are quite a bit different, and I could not make the translation.
I'm guessing I need to make changes to the files in /etc/network,
but I saw indications that these were setup by debian tools and
should not be hand edited.  Is there a config tool I can call to do
these changes?

Thanks, 
jdk