FANHISTORY REFERENCE BOOKS
There aren't a great many histories of SF fandom available in book form, but I
have a small shelf of such volumes. They're listed here for those who might
want to delve more deeply into these matters and are a mixture of books
written specifically about fandom, and books by SF pros that contains
interesting material about fandom.
Mike Resnick also has an interesting article on the topic here.
1. BOOKS ABOUT FANDOM
An honourable mention must also go to WARHOON #28 by Richard Bergeron, a 600+ page collection of writings by 1950s superfan Walt Willis. Despite being a hardbound volume and invaluable to me when I was writing THEN, it's still a fanzine.
2. BOOKS BY OR ABOUT PROS
An honourable mention goes to Isaac Asimov's IN MEMORY YET GREEN, which includes a few details about 1930s fandom.
3. FREE eBOOKS ABOUT FANDOM AND PROS
David Langford has been doing sterling work on the TAFF website, adding new ebooks most months. The above are just six examples from the dozens that can be found here: