Writing is a very personal exercise and there is no single correct way to go about it. Some plan out every detail before they sit down to write, others prefer to let the story flow. I have found that my process is somewhere in the middle. I need to prepare, research, think out characters, and then begin to write once I have a full set of tools at my disposal. One of the most important tools, particularly for writers of genre fiction, is research.
Writers are always told to write what they know, but what you know can be expanded by research. You want to write a medical drama set in 1880s England? Even if you have a background in medicine, some research is in order to understand the state of medicine at the time, the place you plan to set your story in, the social conventions, the dress, etc. When there is so much potential research to be done, it can be easy to overwhelm yourself.
So, the question to ask is: how much research is enough? When it is a topic that you are interested in enough that you think you want to write a book on it, it can be difficult to discern how much research is enough. Spending too much time researching can slow your momentum and make it difficult to actually sit down and write when the time comes. However, no one wants to have glaringly obvious anachronisms, misuse of terminology, or undeniable inaccuracies. The key is doing enough research to be able to sprinkle in enough facts to give the story some a texture and dimension it might lack without proper research.
You can think of research like adding spices to a meal, a little bit can make an average dish taste great, but too much can spoil the whole meal. As fiction writers, the facts add realism and believability to your story, but they shouldn't usurp the attention of the story you are trying to tell. This can be a difficult balance to strike, so here are a few tips to help guide you.
1. Consider Your Existing Knowledge
If you are a massive Jane Austen fan, you may not need to do any additional research to know the difference between a pony and trap and a barouche. Don't waste time researching things you already have a decent understanding of. This can be difficult, as you likely already have an interest in the subject and want to do further research to make sure you get everything just right, but trust yourself!
2. Establish What Information Is Vital to the Telling of Your Story
Consider your major plot points, does anything hinge on specific facts that need to be researched? Is it imperative that you know that you know that the Glock doesn't have a safety you can switch on and off? Does your main character need specific knowledge of the New York MTA system? If any action hinges on knowledge of a specific topic, then that research is essential to the telling of your story. If, however, you simply want to be sure that everything is 100% correct, then maybe you should move on to writing.
3. Don't Become an Expert, Just Get the Answer
You don't need to rival a Ph.D. student in your knowledge of Dickensian London if you want to write a murder mystery set in that time period. Fact-finding is one thing, but setting aside your writing for months to read books, journal articles, primary resources, etc. doesn't serve your end goal of writing. Reading one book on Victorian life? Good background research. Reading three books, two dissertations, and twelve articles in academic journals? Perhaps a bit overkill, unless your story hinges on this kind of minutiae.
4. Know When to Pull the Plug
If you find yourself researching in order to avoid writing, you have gone too far. Being able to recognize when enough is enough is difficult and can take some trial and error. Ultimately, if research is your goal, you should probably be writing non-fiction instead.
These tips are basic, but can help save you from falling down a research hole. While research can add authenticity to your story, it can also derail you from your writing process. Always use research as a tool rather than as a distraction.