AppFusions' co-founder, Patrick Li has three delivered two industry books on JIRA, both available on Amazon:

Further, AppFusions gives back to the Atlassian Community on a regular basis, via Atlassian's highly active community forum,

While being active on Answers helps the Atlassian customer community at large – it also helps us to stay on the cutting edge of listening to the challenges of customers at any given time.

Insights gleaned from the Answers forum are tricks of the trade and industry that are hard to learn anywhere else but there – both technical and beyond! And when you giveth, the community gives back – by way of "Atlassian Answers" karma!