slackware box as gateway/router

hey

i want to be able to point my windoze box to my linux box as a gateway.
there's a proxy (squid 2.5 stable12 RC2) on slackware 10.2 (kernel
2.6.13.4). there's a route from the linux box to the DSL
router/gateway, but i want to put up a firewall or something and using
cacheing without putting in the proxy ip address on every browser. The
gateways on the window's pcs are already set to 192.168.0.1/24 so i'll
change my dsl routers' ip to something else and make the linux box the
new "router". But how do i do it. Details plz cuz i don't know how
gateways work.

I don't want a bridge of the slackware box, i can do that, i want to
have the slackware box as my gateway in windoze TCP/IP setttings.

Local Net Slacware Box
DSL router
192.168.0.0/24 <====> 192.168.0.1/24 <=======>192.168.0.2/24

Thanx