When I went to Waterstones the other day, I stared at the twin categories Crime, vs. True Crime. Placed side by side, they hold an interesting dialogue with each other: do crime story authors, detectives and investigation officers like to read true crime for inspiration?
There is also another intriguing and sad category called Painful Lives. This category occupies a shelf of its own. I suppose the bookstore would need some internal guidelines to help staff find out what books to put under this category. After all, it can be a rather subjective interpretation.
At the Norwich Millennium library, they dedicate an entire section called UFO. A brief desktop research reveals repeated sightings and strange lights reported for the mysterious wide-open skies of East Anglia. I don’t think it is a typical book section for any library. (Ref: http://www.nationalarchives.gov.uk/releases/2008/october/ufo.htm)
Next time you visit a bookstore or library, check out the way they organise the collections.
Jennifer Wong 
Jenny if you can, I’d recommend getting a hold of the television series Castle. It’s about a crime writer who starts working with the police. It’s pretty interesting.
I, too, like to observe bookstores’ ‘categories’. An author once said there really should be just two categories: “Good Books” and “Bad Books”. He said that jokingly.
The Library I really love
In Oakland Chinatown
Is almost always full of people
Young and old they thirst for words
The shelves are divided up
In the usual library manner
But the main language of the books
Is written Chinese
English, is a distant second
along with Korean, Vietnamese
And other Asian languages
Makes me wonder where I am
V interesting, although I have never had the opportunity to go to Oakland myself…