NO, you dont need to download them, nor signed them nor scanned and send them. The only thing you must do is open the file of course its by pdf. then fill up the necessary boxes. validate it. write the name of the (applicant). NO NEED TO SIGN IT since it is an online application. the written name of the applicant is enough in the SIGNATURE FIELD. Validate it.. save it in your computer then upload it to where it at the corresponding field in your application at
www.cic.gc.ca/mycic.
When you are done uploading all those needed documents... you can click continue then PAY by credit card.. Upon payment and confirming your (Confirmation of Online Application Transmission) then you are gonna asked to check the CHECK BOX on there to AGREE for DIGITAL SIGNATURE. That's what it is.
NOTE: If you are gonna download, print and signed them... you better do that for PAPER APPLICATION... that's what the move is for.