Two ways:
The more hard way: install PRIVOXY and configure it to work as a 'transparent proxy' then let other machines on your LAN point the PRIVOXY ADDR.
Simply way: let the program you use on other machines on the LAN and if the program permit proxy configuration, point to machine running tor server as SOCK5 port 9150, if you have not changed it on TOR server configuration. I.E if your tor machine is 10.0.0.1 then let the browser, on an hypothetical 10.0.0.10, set proxy to 10.0.0.1:9150 using SOCK5 mode.
That's it !
AnteGamissu