Riverdale is a great neighborhood and probably one of the best places to raise a family, if you wish to, in the city because of its suburban feel. I'm not sure how it was when you were living around, but it has become a very Jewish neighborhood. Although far from all, a lot of the Jewish residents are Orthodox, or very religious. There are also smaller Irish, Korean, Italian, German, and Hispanic populations. If you live deep in the neighborhood, and you don't have a car, it may take a few minutes to get to the train station to commute to Manhattan. I'd suggest you buy a car if you don't have one because Riverdale isn't like the city at all. No traffic, many of its residents own cars. Riverdale isn't the type of neighborhood where, at night, you decide you want to go to the local bodega or C-Town because you want Ice Cream. There is no local bodega or C-Town. You need a car to get to those simple places, or else be prepared for a ten minute bus commute. Parking may be a problem sometimes in some parts, other parts are relatively easy. There are some decent restauraunts, too, if you're into that stuff.
If you're looking to rent, you can find a one bedroom in some parts of Riverdale for $1250 a month, or a two bedroom for $1650 a month. Some parts of Riverdale are extremely affluent (Fieldston) while others are working-Middle Class (North Riverdale).
I was researching houses in Riverdale, and came across this. A 4 Bedroom, 2 Bathroom house for $2,500 a month. Pretty good if true:
REALTOR.com: Find a Home - Listing Detail
If you can afford it and want to start raising a family soon, a house might be a better option than apartment, unless it's a 2-3 bedroom apartment.