Start by reading here http://www.cic.gc.ca/english/immigrate/sponsor/parents.asp You need to be established in Canada believe for 3 years and able to demonstrate financial stability to support the applicants if required.
Also note no new applications being accepted this year as quota reached plus they are only getting around to applications that were received November 2011 so on that basis once a new application goes in if continues that way not likely not processed until 2021 but add the qualifying period then maybe 2024
Unfortunately, the sponsorship of parent application period is now closed but will re-open on January 3, 2017, with a cap of 10,000 new and complete applications. However, You can apply for a super visa instead, the processing time would be Faster.
A super visa is an option once you are established with a good income, there are conditions to apply and for sure not just landed http://www.cic.gc.ca/english/visit/supervisa.asp will allow them upto 2 year visit at a time.
Right, for super visa, you also have to show that you meet income requirements in the past 3 years. You can however help them apply for a regular visit visa as soon as you land. They can stay for 6 months at a time and after 5 months, they can apply to extend if they want to stay longer. They would not have health care so you'd have to get private insurance for them. With a regular visit visa, insurance is not mandatory but is a really good idea because an emergency illness or an accident can set you back thousands of $. With super visa, health insurance is mandatory.