Hi there,
So as they mentioned here, if u r a canadian u can do it overseas but a PR has to do it from inside canada, I recommenf that u mention the address that you will be staying at when u start the process due to the fact that you will be sending and receiving alot od stuff during the sponsorship process.
Some things you should take into consideration is that you will need to contact the CRA "Canada revenue" and ask them to issue something called "C printout" or something like that I really cant remember the exact name im sorry, but anyways it is something to prove that you r not living on wellfare so call them and ask them because the embassy will ask u for it during the process and you dont want anything to longer the process

)
And make sure that u bring every single document that prove that u have ties in canada, like house, bank accounts, job offer or a letter from yr employer etc...
Look, the main idea of the sponsorship process is to show them that u are not going to live on the wellfare when u & yr spouse move to canada, u have plans like studying and working and ofcourse enough funds to live there, and that ur relationship is really really really genuine so thats why u will need to send alot of photos, mariage certificate, etc...
I sent them tons of photos, wedding, engagement, honeymoon, hangouts and we explained alot of details, so it's not gonna hurt if u send as much supporting documents as u can and the good part is they will return everything back to u at the end of the process.
So good luck in yr process

))