So far my categories are -
Gardening
Art
Travel
Natural History
Novels
Biographies
Childrens
Motivational
Diet and Health
Current Reference (living simply)
Standard Reference
Duplicates (how many dictionaries does one family need?)
Picture Books
To Be Returned
Definitely to Get Rid Of
and (inevitably) Miscellaneous
I like Lynne's idea of a 'core library' (see comments 28 Nov). I now see myself as pruning and thinning and getting rid of dead wood to keep my core library vital, healthy and accessible and with room for fresh growth. (Do you like my gardening metaphors Lynne?)