Based on things you want to consider, I would suggest the following:
Crime Rate
CBC has released some "Crime Maps" which show you levels of crime in Toronto area. You can find this at cbc.ca/toronto/features/crimemap/
Access to Downtown
Somewhere in North York would be advisable because it is not directly in Toronto but still very close. There is subway access from parts of North York, which is approx 40-45 minutes single-ride commute from Downtown Toronto. Also, Mississauga is a good choice because it is family friendly and because you can take the GO Train (a little more expensive, and approx 45-60 minutes commute to Downtown Toronto usually).
Schools
Luckily there are schools in most residential areas within walking or bus distance. Once you narrow down the area you want to live in, you can search in some detail about schools of that area particularly. In my experience, most people do not worry about this as schools are very accessible overall.
Car
Depends on where you are living. If you want to live in more suburban area, car is recommended. If you are living with close access to train/subway/bus, then mostly you may be able to get by without a car. Mississauga has a good transit system, Toronto also does (North York is connected to Toronto by subway). Individually, you can get unlimited travel monthly pass for public transit. But on weekend or with family if you need to go somewhere, you may consider having a car.
Rental Apartment
You can check realtor.ca for reliable rental listings. When you click on a listing, at the bottom you can find something called "Walk Score" which can help you determine need for a car. Alternatively, I can help you find a rental place. I am a Realtor. You do not have to pay me (landlord will pay my fee). I can find you something near subway/easy access to Toronto, good for family, close to schools. Please email me at anujoshirealty@gmail.com with how many bedrooms you need and what is your monthly budget.
Hope that helps. Let me know if I can help with anything else. Best of luck!