Edmunds.com has several "Financial Calculators" to help you estimate what your monthly payment based on purchase price, down payment, interest rate and length of loan. Run the numbers before you go car shopping, and print out the result and keep this information in your car-buying folder. This will show you what you can afford, and prevent salesmen from manipulating the numbers during negotiation.
Edmunds.com also has a True Market Value (TMV®) pricing calculator. Follow the prompts to determine a fair price for the car you are considering. The TMV price is the average negotiated price other buyers are paying for the same car in your area. TMV represents a good price for you and a fair price for the dealer. (keep in mind that US$ are about 1.2 times the Canadian dollar these days)
Some of the information above is in US funds, for US consumers. While the model information will largely be the same.
You will need to convert the pricing. To convert any US dollar prices, you can multiply by 1.2 for approximate pricing.
Some sites require you to enter a US Zip Code to acess their data, try these: