Thanks to Jess Portnoy and others for much of the information below. Also, there are some notes specifically pertaining to configuring a cable modem and cable internet service providers in Israel on Jess' webpage for those that live there. I have personally subscribed to two large cable ISPs in the U.S. without any trouble using the instructions outlined above. The previous incarnation of this document had a large catalogue of ISPs listed by geography, but as a rule the identity of the upstream provider should not affect configuration. If your cable ISP claims not to support linux, it is not because of any technical difficulties related to the operating system. Just don't expect them to configure if for you on your end like they do for most other users (that's why you're reading this document, right?).
This model has enjoyed widespread use by cable providers. There is a separate HOWTO, written by your humble author. Supported by both Ethernet and USB CDCEther. Refer to that document for any hardware specific questions. The generic instructions above generally work.