Do Your Research
In particular, try to find a place to live that's in a location that's not too far from the nearest center of activity. Depending on how far out into the country you'll be moving, the nearest center of activity could consist of a two-lane intersection with a Post Office on one side of the road and a grocery store on the other.
Regardless, it's important for you to not situate yourself too far away from life's necessities. People who have lived in the country all of their lives are well skilled in making a single trip to the grocery store that'll last them a month, but if you were born and raised in the big city you might be used to strolling down the street to the local quick stop on a daily basis. Country life demands a certain independence that might seem alien to you, and for that reason it's not a good idea to go about it in a cavalier manner.
Rent before You Buy
Country life's not for everyone, and you don't want to find out it's not for you either after moving and signing a 30-year mortgage. There are also varying levels of "country" that you might want to try out before settling into a lifelong commitment. What if you arrive to discover that things just aren't country enough and what you really want is a ranch home where the nearest neighbor is five miles away? Renting gives you the freedom to move about and try different arrangements before you make a decision about how and where you're going to live permanently.
Check out Local Schools
If you've got kids, you've got to figure their education into every decision that you make, including decisions about where to live. Rural areas can be great places to raise a family because they'll be away from the negative influences that are sometimes inherent in big city life, but if the caliber of schools is poor you could be doing your kids a greater disservice.
Before moving, also consider your distance to the nearest schools and if that distance is great, find out if there are bus routes that will pick the kids up in the morning and drop them off at the end of the day. Your home's distance to main bus route thoroughfares should also be a consideration, otherwise your children could end up walking long distances to make it home from their new school. If school district buses aren't available, you may have to drive them there and back every day.
Watch Your Step
That goes both literally and figuratively, but mostly figuratively. People are people everywhere you go, and you shouldn't expect that simply because you've moved to the country where the population density is only a single percentage point what it is in the big city that you won't encounter the occasional polluted soul.
You might come to find that not everyone's as friendly in the country as you were led to believe by what you've seen on TV. This isn't to say that people who live in the country are rude, they're just not stereotypes. Take things in stride and do your best to be conscientious to those around you. If you do, it'll only be a matter of time before city life is a distant memory.