Separating Subnets on Cheapo Linksys Cable/DSL Routers

[Mark Street]

I have a guy who has a SOHO that wants to split private network segments in 
his offices.  He has wireless DSL through Broadlink which has the unit on 
the roof that does DHCP, NATand firewalling.

He purchased a BEFSR41 ver. 2 Linksys Router for the inside network.

To keep the inside networks from talking to one another would the best bet 
on the router be separate subnets with static routes through the 
gateway/router and out the WAN?  I think the thing supports 20 static 
routes or so.

Let's say 4 subnets for a 192.168.1.0 network with netmask of 
255.255.255.192, 62 hosts available on each subnet.  Set a static route on 
the router for each through the gateway and out the WAN.

Each subnet would have to set a switch or a router for their own segment.

Am I close??