When I rented my basement suite out I was able to deduct the interest for the mortgage in proportion to that part of the house (40%). Plus I deducted 40% of the utilities, insurance etc. as rental expenses. For your situation, estimate the total income (rent), subtract expenses (interest, utilities, etc.), what kind of paper profit do you have? Use some numbers to get a handle on the scale of the question.
When it was all done I was left with no profit, on paper, since it was all going against the deductions. I never claimed capital deductions because I had enough other deductions. By cutting my expenses by 40%, I came out ahead on a personal basis, that's where I saw the benefits. Plus, it paid for all the interest on the house I didn't need at the time; its now converted to space for my kids to play and my wife and I to enjoy (I was single when I bought the house, my situation improved).
I also had roommates, which is classified differently than a tenant. A roommate shares a kitchen, a tenant does not. Roommate rent is not considered as income. To be clear, are you going to have separate entrances and separate kitchens from your renters? My city would never have zoned me for 2 suites in my neighbourhood, but I was zoned for a single suite (at 40% or less of the total property size).
This advice only applies to an owner occupied house. It is different than a true rental property, the situation is more nuanced and much more beneficial to the owner.