Retweeted this the other day but wanted to talk about it in more than 140 characters:
The importance of organizing your bookshelves
(Yeah, yeah, it's from The Guardian so I know they spell "organizing" differently, but I'm not British and I can't bring myself to do it.)
I think you can tell from looking at my blog that I don't believe in organization. In the background image, you see Esslemont, Erikson, Rothfuss, Lloyd. (It's all a photo of one shelf -- mostly Erikson behind the text in the middle.)
I live in a two-bedroom condo, and one bedroom is full of small animals in cages (well, the iguana is not so small, but he is in a cage). So books are either in the bedroom I use for sleeping, or the living room. I already need more shelf space but don't know where I'll put more shelves. At any rate, all fantasy fiction is grouped together, but with absolutely no logic to which author goes where, except for the cases where I have a ton of books in the same series or by the same author (and inclusion in this list does not have anything to do with liking or not, it's just what I own) -- Wheel of Time, Malazan Book of the Fallen, Shannara, Sword of Truth, Recluce, Glen Cook, Guy Gavriel Kay, etc. In these cases, I try to keep them together on the same shelf. Not necessarily in order of publication (that would really screw things up with Glen Cook because there was Dread Empire, then Black Company, a few standalones, Instrumentalities of the Night, more Dread Empire, etc.).
I also try to keep books out of the vicinity of the litterbox if I can help it. Sometimes the kitties miss. I have some books (mostly little-used textbooks from general education requirements, though my Harvard yearbook happens to be in the area too) with old cat piss on them. Not sure what to do about that, honestly. I'm ignoring the issue until I have to move, I suppose.
Nonfiction? It's everywhere. Most of the science is in the living room now, philosophy is split, fiction that's not fantasy is all over the place, folklore and mythology is sort of together.
I don't like to alphabetize. Since I have the sort of memory that works very well spatially, I can remember where a book is without having to have it organized. I think it drives my boyfriend nuts as he's an alphabetizer and categorizer. Sometimes I wonder what he'd do if I moved some of the CDs in his apartment around. (I wouldn't actually do that, but I tease him about it.) (Second parenthetical remark: I don't have to worry about alphabetizing music, since I have an extensive iTunes library and the computer does it for me. Though I mostly use the "shuffle" feature, anyway.)
Now that I think about it, I've posted on this topic before:
Books on the Shelf
Books on the Shelf, Revisited
Well, what are you going to do about it? With over 200 posts and only me writing them, there's going to be some repetition!