To the outside eye, all four of my bookshelves must look incredibly disorganised. My books are not in any particular order, and even when I have several books by one author, I do not house them together. My books are not arranged by genre, date of purchase, or colour. They merely go where they fit now! Despite this, I still know where (pretty much!) everything is. The only category which is relatively organised is that of my to-read books; I have two distinct shelves on which such books reside, and like to keep them split into fiction and non-fiction, just for ease of picking my next read.
There are a wealth of articles around the Internet about organising one’s bookshelves; this Guardian piece, which deals with the difficulty of categorisation, is probably my favourite.
If you find yourself horrified by the above – which I am sure many do – please let me know how you organise your books. Do you have a system which makes sense only to you? Where do you put your new books, or those which you have yet to read?