Typically you would include your wife and child in your application as accompanying dependents and they would get PR at the same time as you. If you include them in your application as non-accompanying dependents, then you would sponsor them after you land in Canada and become a PR. This process can take anywhere from a few months to over a year depending on their country of origin. Additionally, you must be living in Canada at the time you submit the sponsorship application and must continue living in Canada while their application is being processed.