Your best bet is to find a realtor who knows the area. Make sure they are commercial agents who complete a lot of retail deals. They will have the most knowledge and relationships that will end up getting you the best deal. If you do not have an area in mind you can find companies that specialize in using demographics, expenditure data etc. to pinpoint areas that would give you the best chances of success.
That being said if you you could check out www.torontoretail.ca for more information on this.
