Links .... to sites and resources for Hong Kong's social history.  Sites/collections/libraries I use in my research

Gwulo - putting this amazing crowd-sourced online collection at the top, as its the repository of so much research and information.  A site with over 30,000 pages of Hong Kong's history - photographs, documents, memories, records, enquiries and much more.  Founded, developed and managed single handedly by David Bellis, it amply repays time spent browsing through.
Hong Kong Government Reports Online  - documents from 1842-1941 searchable by name, keyword, date or document.
Hong Kong Public Records Office - out in Kwun Tong, is getting easier to use all the time.  It holds a huge amount of records of every sort.  After eight years I'm still learning my way round the system and never know what gem will unexpectedly pop up next when I'm there.  They do have digitalised records but (access from the link above) but the main ones I use are for paper/microfilm records and the Carl Smith card collection, which can serve as an end in itself of point to the original document.  Its worth noting that more is available in each collection on the onsite catalogues than appears on the external public sites ... all to do with data protection, apparently ....
Old Hong Kong Newspapers MMIS run by Hong Kong Library Service.  English language papers include China Mail, Hongkong Telegraph and Hongkong Daily Post (not the South China Morning Post).  Its searchable and screenshot-able (used to be able to download pages until they got twitchy!).  For every person I come across who likes this site there's another who finds it difficult to get what they want.  I'll write some notes with a few suggestions about effective searching.  
I haven't regularly had access to HKU library, but have found so much in Hong Kong Public Libraries - especially Central Library in Causeway Bay.  The Hong Kong section is very good on the XX floor, together with the Royal Asiatic Society HK Branch holdings. Most conveniently all the old newspapers (including the South China) are on microfilm here, as are CO129 (Correspondence), CO133 (Blue Books) etc etc.  Head up to Floor XX for the XXX And in the special collection section the original Government Gazettes, Hansards etc etc are all available.
I spend a lot of time at the National Archives in Kew, London, where many of the documents that are online in Hong Kong are held in their original paper format.  Particularly useful are the massive tomes of the CO129 series (Colonial Office correspondence papers from Hongkong).  Their catalogue can be searched by all the usual categories.  If you're there and not finding all you want, ask one of the help desks - I find that they are very well informed and love an interesting challenge!
The Industrial History of Hong Kong website is particularly rich with great articles on all aspects of commercial/industrial/working life. Its a fabulous place to go when you want information about a subject that digs deeper than a mere description, or have one of those "I wonder why ... " questions pop up.
To be continued ....