Most writers I know are pretty particular about how and where they write. We like our familiar and comfortable surroundings. We also like our familiar, comfortable and usually very ratty reference books. And we don’t like to change them very often. My copy of The New Roget’s Thesaurus is twenty years old and looks it. Sometimes I’ll use online thesauruses but I don’t find them as useful and comprehensive as my little blue book. I like the fact it was complied in 1912. There’s some fine old words in there that are missing from newer editions. Another book I can’t find a good online substitute for is the Ultimate Visual Dictionary. It’s useful for looking up the names of body parts, ship fittings, geological features, building terms, etc. Nothing can substitute for its clear, well-labeled photographs and illustrations. I find myself reaching for it on a daily basis. Next comes my one-volume encyclopedia for quick, general fact-checking and my field guides for various details on birds, insects, mammals, flora and geology. These I have close at hand at all times. Other reference works depend on the scenes I’m writing. Some scenes need very little: two characters spilling secrets over supper will probably only need a few specialist details to give the scene a sense of place. Battle scenes on the other hand are always a good way to pile up bodies and books.