Hi Comflakes,
We went to this notary public:
http://www.myvancouverlawyer.com/
You'd better to make an appointment in advance.
so I'm talking about my Statutory Declaration of Common-Law Union. If you meant statutory declarations from friends and family, it would be a letter or some other format the notary suggests.
We brought Statutory Declaration of Common-Law Union [IMM 5409] (filled except for signature part and printed) and our each ID.
http://www.cic.gc.ca/english/information/applications/fc.asp
As Rob_TO mentioned that this form IMM5409 is not in Inland application package but in Outland one, but we submit this for our Inland application as we got the advice to strengthen the proof of our relationship.