I'm guilty of the above. I often spend days doing research for a book or even a short story. That often means I am spending more time researching than I am writing. Problem? Yes, it surely is. But there are a couple ways to get around it.
Some things, point of fact, need more research than others. Novels set in a historical time—even if only for a flashback or two—need that research in order to be authentic. But it's easy to be caught up in every little thing that crosses your eyes. Checking, and double-checking your facts, etc.
If you're researching for an era in the past, the best way to start is by making yourself a list. Once you ahve all possible questions you need answered, it will be simple. You won't be sidetracked by looking up food dishes if your main character is a vampire who doesn't eat. You'll know exactly what you need to find out, and once you discover the answers to those questions, you can go about constructing that scene.
Also if your scene is a flashback—especially a flashback in a dream—keep in mind that people don't remember every little detail about the scenery, etc. They recall how things made them feel. After two hundred years, the likelihood of your character having a perfect memory of this particular scene is slim. So slim, in fact, that you have a better chance of becoming pregnant if a person sneezes on you. Therefore, you can pare down sensory details to the bare minimum—what is needed to bring this scene alive and nothing else.
Of course, you may need to do research for things other than just historical scenes. If you're dabbling in paranormal romance, that is a sure sign that you have some sort of mythological creature mixed in, if not more than one. That, if nothing else, needs a bit of research. You have to decide how closely you would like your version of this creature to emulate how history and mythology paints it. And to do that, you have to be well-read. But before you lose yourself in the sea of books you're sure to find on the subject, one way to help is to choose five or six useful sources and gather what information you can through them. Even being well read in your genre can help you to get an idea for the semantics of a certain mythological creature. That, of course, is the most pleasurable way of doing research. If you're a little more practical and want some solid fact, you can make another list, this one consisting of all the things you don't know about your mythological creature and the things you need to find out.
Then again, maybe you're setting your book in a city you've never been to. I try to avoid that as much as possible, which is why my stories are generally limited to three cities—Toronto, Montreal, or Ottawa—so I can follow a very good rule of thumb: stick with what you know. Until you've been to New York City, I don't recommend that you set your novel there. Although you might feel that you are limiting yourself, remember that if a bona fide New Yorker was to pick up your novel and see your bluff, you might turn away readership from that city. Don't bluff unless you're very good at it. Instead, if you insist that that is the only place your story will fit, at least book a trip and take a walk around the city once. If that is impossible, you can always take a peek at Google Maps for a street by street view.
In the end, the best way to cut down on research time is to stick with what you already know. Work within your area of expertise, and build up that expertise as you go along.
If you're not sure where to start? If you're not ready to hit the history books, why not start at the website of one of your favourite authors. Often they'll have a tidbit or two on their website, sharing some research that they have done, such as author Cindy Carroll.
Of course, you can always check back here. In the coming month, I plan to launch a blog mini-series cataloguing paranormal creatures, for those who need a little extra nudge in the right direction.