Ask HN: Any recommended resources to learn online community building?

Oh, these could help:

http://www.managingcommunities.com/

https://www.feverbee.com/richs-blog/

I'd also recommend The Admin Zone as a forum, since it's basically dedicated to community building and forum software:

https://theadminzone.com/

Another site to look out for is Forum Promotion, though mainly once your site has been launched and needs more help:

https://forumpromotion.net/forum/home/

Here's a complete free guide: http://www.communitybuildingguide.com/