For reference today, please see a John Scalzi's article here about a article by Brit music critic Ben Meyers. Short version: Meyers criticized the way the Internet makes research too easy for would-be writers, so you don't get the 'real' experience or facts. Scalzi says he's using the Internet as an excuse for his own laziness. Now despite that Meyers is a hideous arse candle, and Scalzi serves him a heaping bowl of Snarkies for breakfast, this brings up a question:
Say you're inspired to write a story that takes place in ancient Rome. You know nothing of ancient Rome, but that's where the story takes place. That's where it has to take place, because that's just where the story is. It would take months and months of research to get a flavor for ancient Rome. Should you still write it or try a different story that's "not so much work"? (This is under the premise that you don't cop out and do half-assed research like Mr. Meyers. It's either all or nothing, because you're a SERIOUS WRITER).
On one hand, you're not being true to the story if you're not doing the research. You want to write about ancient Rome? You have to be ancient Rome, if you want to be taken seriously. You don't NEED to research in order to write any story, but it can add a lot of plausibility and flavor to it. Stephen King wrote about a psychic girl who hacks up her prom. He didn't need to know about being psychic, or being a girl to write a good story.
But on the other hand. You're an unpublished, inexperienced author who just damn well needs to get some words on the paper. Are you going to invest all that time and money into something that may not sell just for the sake of authenticity? Plus many writer's say you have to just let the story flow. If that's the case, facts may in fact, get in the way. For all the authors that do their research, there are a hundred others that don't (Western writers, period romances, corny war novels) and sell just as well. At least I don't see them disappearing from the stands any time soon.
Stephen King would say research is okay, it adds flavor, but it should never interfere with the story. You shouldn't be interjecting facts you found, if they have nothing to do with the story. His works seem like they require little research and a great deal of imagination. Neither do J.K. Rowling's. What's there to research in Harry Potter? It's all made up! It's a fictional schoold, with fictional characters, and fictional physics. You might argue that time spent researching was spent world-building, but that's not cracking open books and studying theories of magic and mythology. I don't think she needed to know any more about a hippogriff besides what it looked like. That's the thing about mythology, it's very subject to interpretation.
On the other hand, Michael Crichton does TONS of research for his books, because they have more science than dark matter has mass. I was surprised as hell when there WAS a bibliography in the back of Timeline. Many people didn't like the huge infodump about time travel that took up about 1/4-1/3 of the book, but I liked it. It was presented in a good enough way that I know understand how time travel might work (according to current theory). I don't think many people could pull this off though, and it doesn't look like many do.
My judgement: a good imagination is way more important than any research you could do. If the choice is between reading fiction books related to the subject, and research on the subject itself, time would be better spent on the former. I wouldn't let research get in the way of my story, the story that fate gave me to write. Authenticity be damned.