I applied to emigrate to Canada in 2003, and got Permanent Resident status and landed in 2005. The immigration process has changed considerably since I wrote about it. Do not assume my experience will apply to yours.
I also urge you to pay little or no attention to anything you may read in any online immigration forums. Much of the information found in those is outdated at best, intentionally inaccurate at worst. Don't settle for second- or third-hand information. Do your own research at Citizenship and Immigration Canada.
Also my opinion: do not waste your money on "services" like this. You can find out everything you need free of charge.
With those very important disclaimers, these are old wmtc post offering advice on immigration, based on my own research and experience. Your mileage will almost certainly vary.
my advice, part 1
my advice, part 2
my advice, part 3
my advice, part 4
my advice, part 5
my advice, part 6: important!
my advice, part 7: update on part 6
my advice, part 8: new immigration categories
why canada, part 1
why canada, part 2
our story in detail ("immigrating and moving" category)