The Channel 4 Television Corporation (and it's subsidiaries, including More4, Film4 and E4)is a public service broadcaster, and like the BBC publicly owned. It is however commerically self-funded. Channel 4 makes no content itself, but is a 'publisher-broadcaster', meaning it commissions all it's content from independent production companies. If you want to make programmes you are best starting with them. However, this site does have some advice and vacancies on the business and support side: www.channel4.com/4careers/4careers_new/