I had a wonderful time staying at Cecilia and Richard's apartment. They are meticulous about cleaning the rooms and Cecilia is always available for any questions you may have, big or small.
I specifically wanted to experience Kolkata like a local, and I think staying in Jadavpur gives you that experience, i.e. you are close to public transport, local universities, markets, street food galore. You won't find other tourists nearby which was exactly what I was looking for.
Bring a photo copy of your passport and visa as you will need to give this to the host upon arrival. Also, the apartment is tricky to find if you're arriving at night so it's good to get specific directions or have the taxi driver speak to Cecilia, she'll be only too happy to help.