DN12 is actually part of the postal code (zip code). It includes the areas of Conisbrough, Denaby Main, New Edlington, Old Denaby and Old Edlington.
Everyone's experience is different, but I love it here. I have zero regrets about moving. There are little things that annoy me like tiny rooms, no closets and tiny washing machines, but overall I find the living quite easy. The winters are about as bad as eastern PA winters, and milder than western PA winters on average. The summers here, are to me, glorious. None of that scorching heating and nauseating humidity I experienced back home. I hate heat/humidity, but you may love it. If so, you're not going to like the summers here. I've often worn long sleeves and/or a light jacket in August.
In a lot of ways, it is much more expensive to live here. Eating out is, in comparison to where I've lived in the states, exorbitant. On the other hand, I find personal care products (as long as you're not committed to one brand) to be much cheaper on average. You will most likely do a lot more walking here. Depending where you live in Donny, public transport is plentiful (and also relatively clean and nice).
Of course there is the NHS! I imagine with children that is a BIG bonus!
I don't know anything about the preschools or schools there because DH's son is nearly 21, and he was educated in Pontefract.
In the town center of Doncaster is a huge mall (called the Frenchgate), and there are hundreds of shops surrounding the mall that make up the "town center". There is a major train station there as well.
Cantley, Wheatley Hills, Warmsworth and Sprotborough are decent neighborhoods and on the same side of town where your husband will be working. DH said to avoid Edlington and most parts of Balby. DH is cooking dinner
, but he said he would give it "a good think" tonight and see if he can come up with more neighborhoods.