A dedicated fiction writer recognizes the value of research. With the possible exception of paranormal and fantasy, research is a necessary ingredient in the crafting of a novel. But even within the categories of paranormal and fantasy, the writer may find that research is helpful. For instance, in my fantasy romance, "Night Secrets" one of the main characters--Radegunda--is a healer. A book on herbs gave me helpful information and added to the authenticity of the character.
This is as good a place as any to mention the internet, where all kinds of information are available with a few clicks of the mouse. However, most of my writing occurred before the advent of the internet. Really, in conducting research, I prefer the richness and quantity of information in the printed book. Your local library will surely carry books on virtually any subject. Then, too, a writer can build up quite a voluminous library of her own to refer to time and again.
Nowhere is research more important than in writing a historical novel. No fudging on facts in this genre, no guessing. The writer must do more than an adequate gathering of facts; she must fully capture the essence of the time period. If a writer presents any inaccurate information, you can bet that one of her readers will catch the mistake. This is a sure way to lose your readers. My historical romance, "Destined to Love" takes place near present-day Pittsburgh during the French and Indian War. In preparing for this novel, I read everything I could find pertaining to the French and Indian War in that area. Since much of the action happens in an Indian village, I read about the Lenni Lenape (Delaware) Indian. I even studied the language. Books on pioneer life in Pennsylvania, life in the colonial period, clothing and so many other books proved quite helpful.
My time travel romance, "Dream Weaver" takes place a few years after "Destined to Love" and essentially in the same area. So many of the research books I used in writing "Destined to Love" also provided good reference material for my time travel romance.