Besides your own name, that is. Recently a writing friend asked me whether I did all my research before starting to write a book, or as I went along. Well, both actually. It's a never-ending process. Usually, I do a few months' research on historical events and figures first - highlighting books and writing notes. Then I type up a timeline, chew on it for awhile and fish out where the story lies. An outline emerges and while I'm writing the story, I stop and look up specifics that will flesh out the scene. Often, when I'm getting the bones down, meaning the action and dialogue, I just leave 'XXX's or [MORE HERE] - notations that tell me to fluff it up later.
So, I counted more than 70 books within arm's reach: biographies, historical non-fiction and resources (wildlife, locale setting, castles/abbeys/monasteries, weaponry, food, knights, warfare, costumes, medieval life, etc.). I've probably checked out as many again from the library. I once had a system going for which I had G.W.S. Barrow's Robert the Bruce checked out for nearly two years (it was an out of print book and money was tight). When it was overdue, I'd return it and then go check it out again the next day and renew it three more times. Wash, rinse, repeat. Fortunately for me, no one else in Springfield, Ohio at that time had the same obsession I did.
There is no more room on my wall shelf for books, so there are stacks on top of the properly lined up books, stacks on the desk, and stacks on the floor... along with spiral binders and loose papers of printed web pages. I love my books, but sometimes I just need a tidbit and so I surf the net. It occured to me recently if the FBI ever confiscated my computer, they'd find some weird internet searches on it: 'pestilence', 'trebuchet', and 'medieval execution'.
Research certainly slows the writing process down, but it also enriches what you're writing. And I enjoy it because I feel like I'm always learning something I didn't know the day before. So what do you Google when you write?