Plants are good for you, we probably have all of the medical and scientific things and personal accounts we need to know that, and Growing Cannabis is legal in most of Canada, and so is purchasing seeds.
Grow with respect to fire codes, and watch for mould, and your health and the health of your home, if you do so indoors.
It is not legal to grow Cannabis in the Province of Quebec (without a Cultivation Permit issued by Health Canada). It is legal to grow Cannabis in Manitoba, with a medical permit. Anywhere else in Canada, people can grow a maximum of 4 plants per household, and must be of legal age for Cannabis.
1. Ensure Smoke Alarms and all of your equipment, is in good working order.
2.Make a Plan for Ventilation and inspect for mould on a ongoing basis.
3. Ensure your Carbon Monoxide detector is in good working order
4. Use a Grow tent.
Or you can put it in a pot, and just move it around your house or keep in a few spots, indoors and out.
Seeds are pretty simple, indica or sativa.
Indica for the body, Sativa for the more mental aspects of cannabis use, Hybride is a bit of both and inbetween.
Autoflowers for easiest growing.
the best info about indicas, sativas, and hybrides can be found here on the SQDC website.
Grow Outdoors by the OCS
Weed Maps Guide to Growing Outdoors
(Fairly Comprehensive, for an Introduction)
The Government of Ontario puts out a starter's guide which will give you a basic understanding of what is involved and what you will need to grow your own interest.
Unfortunately you can not purchase seeds from the O.C.S.