Start by reading here:
http://www.cic.gc.ca/english/information/applications/fc.asp You will need to complete all 3 parts of the application listed there. You would be applying to sponsor your wife for permanent residence (PR) in Canada. She is eligible to become a citizen after she has been a PR for 5 years. Unless your case is complicated, it's not necessary to hire a lawyer. The application is time-consuming but most of us completed the applications by ourselves with no problem. Good luck!