I am interested in the history and genres of fan fiction. Are there any good books and/or websites that could enlighten me?
Depends on what you’re calling fan fiction. Certainly in pre-writing times, storytellers would take established tales and put their own spins on them. In more modern times, I think that almost all writers have dabbled in fanfic at one time or another.
The genres are as varied as the original works they’re based on. One that is massively popular right now is A/B/O or Omegaverse fic. You can read about that here.
You might also find more information at the Archive of our Own (AO3), a community dedicated to fandoms and to fanfic.
I found The Fan Fiction Studies Reader on Amazon. The comments say it is a compilation of earlier articles, so they would be useful for further reading.
Thanks to the both of ye! Between those sites and another that was just recommended to me elsewhere (fanlore.org) I think I’m off to a good start.