Anita29,
Congrats on your upcoming wedding!
Just to clarify, by sponsoring your spouse and being approved, he will receive Permanent Residency in Canada. In order to receive Canadian Citizenship he will have to be in Canada for 3 years worth of days in a 5 year period in order to apply.
As mentioned above, get a copy of the application kit. If you go to the CIC website,
Welcome Page | Page d'accueil, you can request a complete copy of the application kit (there are different applications depending on the region of the person you are sponsoring) and they will mail it to you.
This kit will have all the application forms, a guide and information on where to find doctors that are approved for the medicals.
Read the application, re-read it and re-read it again. It is not too difficult that you cannot do yourself, however, you need to pay close attention to all the instructions and everything that they are asking for.
You can spend some of your time now gathering the items that you will need for proof of relationship and other items that you will need for your part of the application.
Many of us have taken the application with us and filled it out after the wedding, had our spouses sign all the papers and then brought them back to Canada to send to CIC Mississauga.
You might also check the sticky thread on getting organized for some helpful tips.
Best of luck