Just as one would expect, the greatest research on local Hong Kong culture, language, politics, etc. is found within Hong Kong universities, more specifically, graduate and postgraduate papers written by students and professors.
While of course, reading academic literature probably sounds like a dull pastime, the specificity of the topics the papers cover can have much more appeal to a specific interest than a general and far-reaching paper might; for example, I wish to learn about Cantonese linguistics rather than linguistics as a whole. For those who might feel interested in such specific topics as I am, I have recently realized that there is a ton of such up-to-date and accessible material specifically concerning Hong Kong online.
Seven Hong Kong universities and the University of Macau provide online access to many academic paper abstracts, and sometimes even their full texts (many of them are also in English): http://library.hkbu.edu.hk/electronic/libdbs/dol.html
Hong Kong University has its own database of academic papers too: http://hub.hku.hk/
Personally, I hope to read “A study of written Cantonese and Hong Kong culture” by Wu Fung-hoi soon and other papers regarding Hong Kong’s unique identity and Cantonese in the near future.