High-level introduction: http://www.cloudera.com/videos/intorduction-hbase-todd-lipcon
Summary of broader Hadoop ecosystem/landscape:
- Introduction to HBase (video), or a more technical introduction from from 6m30s into this Hadoop Ecosystem Tour video
Follow these instructions http://hbase.apache.org/book/quickstart.html#shell_exercises but note that HBase is already running so you don't need to start/stop it.
For more information on the HBase shell, see http://wiki.apache.org/hadoop/Hbase/Shell