There is one site that's about television in Hong Kong. But first of all, it's in Chinese; and second, there's actually a lot of clips of there, but the site doesn't have a section that talks about the history of Hong Kong TV. But anyway here it is...
http://come.to/hktv
Just some background info...
TVB (Television Broadcasts) runs 2 terrestrial channels: TVB Jade (Cantonese) and TVB Pearl (English). Launched in 1967.
ATV (Asia Television) also runs 2 terrestrial channels: ATV Home (Cantonese) and ATV World (English). Launched in 1957 as subscription service Rediffusion (not sure if it was related to the Rediffusion in London); changed to terrestrial in the early 70s, and rebranded as ATV in the 80s.
Hong Kong Cable is the cable service provider. It also runs several of its own channels.
RTHK (Radio-Television Hong Kong; government-funded) does not actually operate a TV station, but makes programs that are required to be aired on TVB, ATV and Cable.