Check it out!

Check it out man! This was a common colloquilism of the '60s and '70s that was often used when you wanted someone to take a closer look at something or listen more closely to what was being said. Check. It. Out. That simple piece of advice is never more important than when it comes to your writing.
  When you write for publication, whether it's fiction or non-fiction, you are in essence asking the reader to trust you. You're like a doctor, lawyer, engineer, architect... a person who is being trusted and relied upon to know what he or she is doing. A reader is often going in blind when they delve into your writing, and they trust that you respected them enough to do your research long before you declared your work "finished." To not check your facts is the height of literary hubris. Even in fiction, although you are asking the reader to suspend belief whilst they're caught between the covers of your next bestseller, few things are as jarring or disappointing as coming across a glaring inaccuracy while you're reading.
  I'd like to present two examples of what I mean (no doubt you can remember a few you've come across as well):
  1. A very well-known author, a master storyteller in fact, once wrote a story which featured New York City as the location. This author did only a minimum of research into that location even though he didn't live in that city. As a result, once his story had been published, he and his publisher received a load of missives from disappointed and even angry readers who felt let down by the many geographical inaccuracies that were in the story. I believe (see, I didn't do my research here) that the same story also featured someone screwing a silencer onto their revolver. A glaring error since a silencer cannot be screwed onto a revolver.
  2. This next one is a little personal. Many years ago (before I started working for NYC Transit), I was employed by a Wall Street insurance firm. While there, one of my jobs was writing and editing insurance forms and contracts. One of my co-workers was an aspiring novelist and she would occasionally bring parts of her manuscript over for me to read. One day she announced that she had finished her novel, and so she printed out several copies of it and handed them out to co-workers. I put my copy away in my desk drawer figuring I would read it later at my leisure. A couple of days later I saw her in an animated discussion with some other co-workers about something in her book. When she spotted me she called me over and announced to everyone that I would vindicate her and her writing. "Lopez," she said, proudly puffing out her chest in anticipation of my answer. "Isn't it true that Puerto Ricans eat roaches and consider them a delicacy?" Mortified and insulted, I sputtered and spluttered in the negative. The would-be author was confused since this practice among Puerto Ricans was common knowledge in her household (a household devoid of Puerto Ricans by the way) and was something told to her by her parents since she was a little girl. "You," I said. "Should have done your research before putting something as inaccurate and potentially inflammatory in your book." She kept insisting that she thought this particular practice among this particular people to be an absolute fact.
  Well, I don't know if she ever removed that from her novel or if she ever became a published author, but I do know that as writers we have a responsibility to our readers to research our information and check the facts before we declare our work finished and ready to be presented to an unsuspecting world.