Not knowing what country your spouse is from, and not knowing if you are applying in Canada or outside of Canada, I cannot tell you which guide in particular to review; however, you really need to read the guide well, in particular, paying special attention to the checklist provided for the application you will be submitting. In most cases you do not provide the actual Birth Certificate, but a notarized copy of it - in English or French, if it is not in either of those languages originally.
Please see this link to see the guide you need:http://www.cic.gc.ca/english/information/applications/index.asp