It is a good idea to begin with the README and the HACKING files.

A mailing list has been set up for those requiring help with libnjb and it's sample applications which can be reached here :

Before writing, please take some time to browse the archives which contain a few answers in terms of configuration. You can also take a look at the article about setting up your Zen with libnjb and gnomad2 available on the gnomad2 official site.

You can also subscribe to the list here.