Ashish Thapliyal links to a 30-minute presentation on HBase optimization:
This session was presented by Nitin Verma (Sr. Software Engineer) and Pravin Mittal (Principal Engineering Manager) @ HBaseCon 2016. The session goes deeper into success story of enabling a big internal customer on HDInsight HBase.
HBase design is a totally different mindset from relational design, so you have to unlearn a lot of habits when moving over to it.