One of the most common pieces of advice to novice writers is to write what you know about. As cliched as that might be there is some truth to it, which is probably one reason why it is bandied about with such frequency. John Grisham writes legal thrillers and has a law degree to back that up. As a matter of fact, I heard recently that he has returned to practicing law (not exclusively, he’s still also writing). Dick Francis has penned numerous mysteries that all revolve around the world of jockeys and horse racing. Francis is a one-time steeplechase jockey, himself. John le Carré, the consummate spy novel author, worked for British intelligence at MI-5 and MI-6. I looked all of this up to make sure it was accurate.
That being said, if you are writing a novel about a serial killer I am not suggesting that you conduct your own murder spree. You might, however, want to do some research into the mind of a killer. You could read Truman Capote’s In Cold Blood, for instance. There are certainly shelves of books on the infamous such as John Wilkes Booth, Jack the Ripper or Son of Sam.
If you write a boy-raised-by-wolves story, you should have a good idea of the habits and rituals of wolves as well as where you are likely to find them. Setting your wolf story in Arkansas might earn you a bit of criticism if Minnesota and up into Canada is the region where wolves live.
In a story or two I have used a vintage car as part of the plot. I downloaded photos and facts about that make, model and year of that car so that I didn’t insult any car enthusiasts. Pictures helped me describe them down the chrome side view mirrors and bench seats. I even looked up what colors were available that year so that I didn’t inadvertently have my protagonist driving a car in a color that didn’t exist. I know it’s not going to impact the story if I describe a green 1968 mustang and someone knows that green wasn’t one of colors that year, but I feel better knowing that I have made an attempt to be true to my story.
If the wilds of an area figure prominently in a novel then you might want to find out what flora, fauna and insects are native to the area you have set your story in. Yellow Headed Blackbirds live mainly in the western half of the US so one should not make an appearance on the East coast.
Be careful of anachronisms. A cell phone was not common before the early or mid 1990s and the ipod was not born until November of 2001. Don’t bring either into play until after those dates.
It all boils down to doing your homework and making sure that all of your details ring true. With access to the internet you can easily do a bit of fact checking. To describe a specific place you can visit it but if a trip is not in your plans you can at least take advantage of Google earth and do a “fly over” and use street view to get a sense of what a town or city is like. As Scully and Mulder know the truth is out there and you can find most of it on the internet. Why not take advantage of it?