Depending on the province you are going to live in, healthcare system requirements vary. In BC, ON, NB and Quebec there is an approximately 3 months waiting period (in BC it is a little different however) before you can start receiving provincial insurance benefits.
In case you are settling in one of the mentioned provinces, you may want to consider getting yourself and your family insured with a private insurance policy for New Immigrants / Visitors to Canada. Such insurance covers the costs for medical emergency treatment and will be a good thing to have until you get the provincial insurance coverage.
You can click on the following link and calculate a personal quote -
Medical Insurance for New Immigrants
Hope it helps