*you need to send original PCC and medical test forms received from doctor and everything else can be photocopy (dont send original marriage certificate, school certificates and passport)
*in case of photos, they dont count but they would like to match your story with the photos. include photos from each and every trip or functions you mentioned in your application forms. in case of indian applicants, they want to see all rituals of religious ceremony in photos (i sent 150 photos all together, 50 from marriage)
*you can send emails with imp. and serious chat about relationship, marriage or future planning, no need to send all. (i sent them screen shots of my gmail home page not the body paragraph of individual email)
imp. docs, which can create problem if missed are-
*PCC
*medical results
*payment receipt
*copy of marriage certificate and wedding invitation card (if available)
*sponsor's proof of job or financial ability
*option-c printout (if available otherwise send letter explaining the reason for not providing option-c)
*copy of sponsor's passport and citizenship or PR card.
*enough proof to support your relationship and your statements in application forms including emails, chat, flight tickets and photos.
*one story from both of you (explaining everything in detail after your first contact)

*reference letters from parents, and friends to support your relationship and future plans
*letter from sponsor's parents or friends stating " you can stay with them after moving to Canada until you find your own place and job in Canada.
im not sure if there is anything left :

:

i think you should wait for few more replies before you send you application (my memory is not so good ??? :-X not sure if i have listed all imp. docs or not)
And copy all the forms and supporting docs before you send your application.
good luck