here is what i'd like to do. i don't know how hard it is/what will make it easy.
ideally:
one box as firewall, NAT (internet sharing to the LAN), server AND enabling a DMZ (second network zone). so, with one public IP address, i would want (e.g.) http requests for lin.myoffice.com to be hosted by this server, but http requests for win.myoffice.com would be passed to a windows box (through a separate NIC then the one used by the local LAN?). The local LAN clients would be able to access the both the windows box and linux gateway/firewall/server.
I've got mandrake 8.2 handy, and I've come across firestarter on the internet (looks like it would help?).
so, how do i get from a blank machine to where i want to be? I'm neither terrified by the command line or totally comfortable with it.

thanks in advance

I'd look into smoothwall, it's pretty simple to set up and I believe it's configuarable to do just what you described. I'm using it for connection sharing/filewall/intrusion detection and it's both dead easy and seems to do a fine job. It will log portscans. etc.

You would have to set something up w/ some sort of DNS provider of course. I've seen references to free ones...

This should probably have been in the Networking forum though

yes i've looked at smoothwall (and you should check out ipcop as well). they're great, but i'd like the same computer to ALSO be a server (w/ php/mysql). that's the tough part.