The income side is straightforward: rent received from a room is reported as rental income, and you can deduct a reasonable share of expenses like utilities and insurance proportional to the space rented out, the same way any partial rental income is treated.
The exemption side depends on degree. A single room rented casually within a home you otherwise occupy is generally treated more leniently by the Canada Revenue Agency than converting an entire legal secondary suite to a full-time rental, which more clearly separates part of the property from personal use.
This is general information, not tax advice, so a tax professional should confirm how your specific arrangement applies, separately from the City of Saskatoon's 80 percent property tax assessment, which is unaffected by an informal room rental. Get your hand-reviewed valuation from Joel Dyck.