I just looked at Amazon’s “online communities” search results, then found this thread on Meta and realised people read books about community building 
I do believe real practice will work as a good book: by doing before even reading you gain subtle knowledge that you cannot describe in words. Sometimes you just know you should do this and that and it will work.
Still, I’m a big fun of books and wanted to say thank you to everyone who posted their recommendations here.
I’d like to also recommend reading the Discourse use-case blog post series and moving from Facebook to Discource. Even though these are mostly marketing material, there are plenty of interesting things and ideas to take out of the articles.
There are also online communities where people mostly share their experience in building, well, online communities (e.g. FeverBee). As well as the whole community category here at Meta. Not sure why but intuitively I always believed that reading about real people’s experience and failures will teach you a lot and is more diverse than reading about online communities in books. Now, since this thread is quite old, and there are some people who read one or more books, one thing I wanted to ask you is to share your feedback: did the books turn out to be useful in practice for your work on community building? Asking for something aka post-mortem re reading those books.