Most med schools require that you complete a 3-year undergraduate degree.  Some require a 4-year.  Some schools require particular courses, such as 1st-year chemistry.  Others do not – however, if you need the MCAT to apply, you may want to choose courses that will help you prepare for it.

Med school is typically a 4-year program, but there are some 3-year MD Undergraduate Programs (eg Calgary, McMaster).  Then, you have Residency which is where you prepare to practice in your area of medicine. This is a minimum of two years - see http://www.carms.ca/.  Some students go on to do Fellowships and other degrees.

More info is available at:

Canadian Federation of Medical Students (CFMS)
http://www.cfms.org/pre_med/index.cfm

• Good intro about what doctors do, what it takes to be a
  good doctor, how long it takes to become a doctor, and
  how much it costs
  http://www.cfms.org/pre_med/doctor.cfm
  
  
• Applying to med school
  http://www.cfms.org/pre_med/application_process.cfm
  
  
• Feedback from other students about each school’s interviews
  http://www.cfms.org/pre_med/feedback.cfm

Canada Jobs
http://www.canadajobs.com/articles/viewarticle.cfm?ArticleID=1255
Good intro about becoming a doctor as well as med school requirements and fees

British Columbia Medical Association
https://www.bcma.org/medical-careers/how-become-a-doctor
Good intro about becoming a doctor, focus is on UBC

Information Centre on Aboriginal Health
(INAC – provided by NAHO)
Health Careers Database page: http://www.icah.ca/content/en/careers/

Canadian Premed and Medical Schools
EZboard http://www.premed101.com/forums

Doctor Starter
http://www.doctorstarter.ca/