I currently run a linux router, smoothwall .org, that does DHCP, port forwarding, firewall, and web proxy. I have a DSL line comming in that goes into the linux router, then out to layer 2 switches and hubs. We recently just grew to over 255 users, so I changed our subnet mask to 255.255.0.0. The router now does DHCP from 192.168.1.2 - 192.168.2.100.
I would like to be able to add multiple linux routers throughout the network to subdivide and subnet the network. (ex. 1 subnet as 192.168.1.*/255.255.255.0, and another as 192.168.2.*/255.255.255.0). They all also need to do filesharing between all computers. Could anyone offer and advice or articles on how to do that?

What do you want to achieve by subnetting the machines?

Presumably you are using the windows network neighbourhood for sharing files.

If the machines are set as peers in a workgroup then you will find the machines won't see machines in a different subnet in network neighbourhood. The amount of broadcast traffic created by a few hundred
windows machines using workgroups is incredible, time to consider a domain.

Although some people might consider it heresy, I'd seriously consider hardware routers rarther than linux box's. Single purpose box's with no fans or harddrives are generally less hassle and use less power.

My understanding is that by subnetting, then network would be divided into more managable parts and would be more routable (less network traffic).

I am using windows network neighborhood for sharing files. I have about 50 Windows computers on my network, and about 220 Apple computers (ranging from OS 9 - 10.3).

Is there any good information out there for converting a peer-to-peer network over to a domain network?