Current project: Nine-book contemporary romance series
For me, research is a potpourri of methods that includes interviews, reading books, visits, and searching the Internet as well as my life experiences. It's fun and easy to get caught up in--as others have mentioned.
I'm working on a nine-book contemporary romance series, so have the careers, hobbies and backgrounds of nine heroes and heroines to research.
Several of the heroes are in law enforcement, so the Citizen Police Academy I attended will provide much of the background material for these characters. I've also printed Minnette Meador's recent interviews with Portland police detectives for additional information.
Since each of these heroes has a different speciality, I'll search out LEA personnel in those areas to interview.
The heroes will also differ in which agency they work for: State Police, big city police department, and rural sheriff's department. I'll do more research on the Internet to get a general feel for how each of those law enforcement agencies work.
I also have a bookshelf of books relating to police procedures, the "language" of law enforcement, and anecdotal stories from real police cases.
I'll do similar research for the careers, hobbies and lifestyles of the other characters, as well as draw on my life experiences. For instance, one of my heroines is a social worker. I spent twenty years working for a social service agency, so have a lot of background in that area.
While much of my research is done before I do the bulk of my writing, other interesting tidbits will come up as I write that I will also research.
Yes, research can be fun and addictive. However, for me that's balanced with the excitement of actually telling the story. That means I don't get stuck in research, but I do have a good time on that part of the writing journey!