You probably want to start on Immigration's website if you're at the point where you need to know which form you need to fill up.
By the way, if you're in Hong Kong, drop by the enquiry counter and they have experienced and senior immigration officers who will answer your questions VERY accurately.
Generally speaking, there is no such thing as too much information, as long as its relevant to the job and your application (they don't need to know when you lost your first tooth for example..).
Reference letters are usually copies of whatever you have available to you currently as a reference letter... "to whom it may concern" is ok.
You do need copies of degree certificates. Certified copies are ok if you cant find your originals.
Don't think you need to write a personal statement... you only need those for grad school and cyberport tenancy applications.
