There is no question that an understanding wife is key. But, it can be done. My wife and I matched the same year...she waited until after I matched to find out what city she needed to interview in for pediatrics. We got married during medical school and had our first child right at the end of our fourth year. We did have a nanny during residency, and it was fairly costly, particularly given our resident salaries. But, my wife finished her pediatric residency in 3 years, and then got a job in a pediatric private practice. This helped support us (and our nanny) while I finished my training.
Neurosurgery residency, even the most benign, can be brutal at times. I trained at an excellent program that is also widely considered to be a 'gentleman's program', but this was before the 80 hour work week. We had times where we worked 5am-10 or 11 pm and took call every 3rd night. I agree that if your wife is independent and can take care of the household and plan the day to day schedule without you, all the better. If you are there, mo' better.
We had 3 more children during my 6 year residency, then moved for 1 year for my fellowship. I then took a private practice position, and my wife cut back to part time pediatrics. We then had 2 more children (for a total of 6), and my wife quit work entirely after the first of these. Now, I have been established in practice for 6 years and make a decent living. I can set my own schedule and take off whatever time I want. We have 6 great kids, including a daughter who just started high school, all the way down to an 11 month old. I rarely miss a sports event, including varsity tennis, JV field hockey, 2 separate midget football teams, baseball games, lacrosse, etc....
If you can see the forest through the trees, there really is no "good time" to get engaged, married, or to start a family. I would say do it when it seems right, and worry about the rest later.
). The residents are in-house far more than any other service - and needing an understanding spouse cannot be understated. 
