This is a question that plagues most writers, no matter how their brains are wired. It can feel like a bottomless well of information when we go down the research rabbit hole finding unusual facts and interesting trivia that may never find it’s way in your story but is arguably making it all the richer with the wealth of knowledge you’re collecting. There is no set stopping point, for some topics there is no end to the information you can uncover. Rather than trying to find a physical stopping point - after this website or after this one book, for example, use a time limit.
This is based on the Pomodoro Method, and if you’ve been following along, I use it for so many things from writing to cleaning to editing. And it’s the same for research.
Use The TomatoSet the timer for 25 minutes and go nuts with your research. When your time is up take a five-minute break to summarize what you’ve learned. Put facts into categories (for example, you could use Vital, Interesting, Need To Know More, and Not Sure), then decide what you need further info on for this specific part of the story you’re working on, and what can wait for a later research session.
If you need more research time, you can reset the timer for 25 minutes but with a focus of only on that one particular area you need for the immediate use of your story.
Dealing With TangentsIf you find something incredibly interesting that you need to know more about but isn’t related to the immediate part of your story put it in one of the lists you created earlier.
More than an hour of research can overload your brain, and suddenly you have too much to work with and no clue what to do with it all, or it starts to blur together and you’re not sure if you’re going in circles.
This strategy takes practice to learn how to categorize and priotorize research, especially when first delving into a topic but it’s more than worth it to keep your focus on where it needs to be and give yourself time to organize your research so it doesn’t end up a muddled mess later when you’re trying to recall what you need.
Good luck and keep writing!