how to turn Mandrake 9.0 into an ISP
 

I'm a newbe so bear with me. I want to hook up a Linux Mandrake 9.0 box to the internet through a cable modem (<-- easy part) and to a phone outlet with the phone modem. Next I want to be able to dail straight into the linux box useing a phone modem with my laptops running Win XP and 2000 pro. to access the internet using the cable modem on the linux box (I know it won't be as fast, but it will save me money). Can it be done? and How? Remember i'm a newbe.