My 21st book will be coming out later this year and all but two of my books have been historicals. I tend to choose topics that I am intrigued by but don’t know anything about. The good thing is that each topic can branch out into more than one book. As an example, I’ve got three young adult novels set during the Armenian genocide, as well as two full colour illustrated chapter books about 50 orphaned Armenian boys who were rescued by Canadians after the genocide. I also have written a number of novels set during WWII, and they are interconnected in the same way.
I have an extensive collection of reference books and these I keep on my office shelves according to broad subject.
I also have a huge collection of photocopied books, transcripts etc — things that cannot be purchased in book form so I got them via inter-library loan and made a personal copy. These I keep in labeled grocery bags — ie one big grocery bag per general topic. I used to keep them in a filing cabinet but I ran out of space. Also, I found that the grocery bag was more portable.
I keep steno pads, but not for writing out anything in books that I am able to own. The steno pads can be for first person interviews, or expert interviews, or they can be for taking notes when going through audio and video tapes, and mircoforms in archives and museums. I have dozens of steno pads so I make sure to label them, then store them in their appropriate grocery bag. If I end up having to take notes in one but for a different book, when I go home I tear the pages out, staple them together, label them, and file them in the proper book bag.
I immerse myself in research before I begin writing, but once I plunge into the story I try not to go back to the reference material until I write myself into a corner. Then I do research just for the very next scene or sequence, then immediately write it. Stopping and doing more research than that is just a form of procrastination.
As my story develops, I do insert footnotes for myself and my editors so I don’t forget where I got the info. Keeping up on this as I go really saves the fact checkers a lot of work at the end of the process. It also save me from having to verify the errant tidbits.
When I’m writing a novel, my writing spots — the tread desk, my lazy boy in the family room, my work space in my office — all fill up with books and papers. I’m like a bird with a nest. Once the novel is entirely finished, right down to the copy edit and page proofs, I put everything back into the bags and onto the shelves. Everything looks clean for about 6 weeks, and then I start all over again.