networking help

[hakuin]

From atomic maganine I am trying to create a file server following the tutorial,with mandrake 9, but at the window of giving ip address i say 192.168.1.1, so i do that but want the ip gateway, what is it and what number should be, because without does go to the next step, i want to make linux the internet gateway too, do i have to put first on nic and after the second one or set up first the file server and after install the internet, I have an adsl with igreen net, the linux box should serve a xp machine , win98 and win2000
thanks for any help, please i want learn desperately linux
E N Z O

[mdwatts]

Usually 192.168.1.1 is the gateway address.

#!/bin/sh
#>>>Device type: ethernet
#>>>Variable declarations:
DEVICE="eth0"
IPADDR="192.168.1.4" <--- MY IP ADDRESS
NETMASK="255.255.255.0"
NETWORK="192.168.1.0"
BROADCAST="192.168.1.255"
GATEWAY="192.168.1.1" <--- MY GATEWAY
ONBOOT="yes"
DYNAMIC=""
#>>>End variable declarations