connecting Linux to Internet via DSL

I have a old computer that I am trying Linux on and I have a small ethernet network at home which consists of a DSL modem, a Hub and my patch panel. I have to Windows computers that we connect to the internet with and I want to add the linux box. My DSL provider assigns the IP address dynamicly. I don’t need to do anything special to get a windows pc to use the DSL but I don’t know what to do with the Linux