This was originally posted by CanadianMom and deserves to be a sticky so you don't miss out on the useful info:
Government site that is useful for all on job prospect /wage questions is www.jobfutures.ca
It has the government statistics of average wages-high and low, and career outlook. Plus useful links for getting trained and links to services Canada (info for immigrating and credential recognition) etc. You can search by career title or national occupation codes(all occupations are broken down to categories).