So what's a good book to have next to your computer? Yes, I know there's some irony in the idea of keeping a book next to the computer. But everything is not digital yet, and so here's a quick jog through my Most Useful Reference Books:
The Visual Display of Quantitative Information. No other book I have ever seen shows you how to accomplish so many useful things in so succinct a fashion. This is the book to have at your elbow if you're a UI engineer, a web designer, a graphic artist — in short, if you're dealing with representing information visually, period. And "information" doesn't just mean statistics, either; it also means ideas, concepts, whacks-on-the-side-of-the-head that you might not get by simply reading words cold off the page.
Strunk & White's Elements of Style, 4th Ed. This book does not teach people how to write; that's something far too broad to glean from any one book, and far too complex to be distilled into such a thing anyway. What it does teach you is how to refine and clarify your writing with simple and specific advice. Use the active voice; don't fight syntax; cut to the heart of your meaning first and work outwards from there. His advice is to be applied in the moment, not simply mused over. It's also remarkable how little the book has changed. The glossary of misused and tired words received a slight makeover since the last edition (which was published in I think the 1970s), but the bulk of Style's style remains as classic and timeless as a tuxedo. And to think it's still barely over a hundred pages, including the index and front matter.
Bartlett's Familiar Quotations. It's grown a bit top-heavy with pop-cultural cruft (no, we do not need an in-print replacement for the IMDB Quotes section), but it's still a fine way to put a name to that phrase on the edge of your tongue or to find a new bit of wit to keep the last graf in your essay from coming down with a bump. Quick: who was it that said "A cynic is someone who knows the price of everything and the value of nothing"? No, the real author. Misattributation is a bugger.
Merriam-Webster Visual Dictionary. For anyone who's ever pointed at something and muttered, "What do you call that thing?" Which, I imagine, is just about anyone reading this. It's one of those reference books that you can get lost in without feeling like you're simply trying to acquire useless knowledge. (In the same vein is Descriptionary, which is a worthy companion to this book.)
I've also been tempted to recommend at least one dictionary and one desktop encyclopedia, even if those things have become almost entirely eclipsed by Internet references. There's a value in having a work that represents a snapshot of professional opinion, and isn't constantly being revised to reflect the prejudices of the moment.