I'm investigating technologies to use for my data warehouse and am particularly interested in the visualization of the data for my end users. Where are some good Zeppelin resources?
Here are a set of zeppelin notebooks that you can start with. https://community.hortonworks.com/repos/4415/zeppelin-notebooks.html
If you haven't installed zeppelin yet, instructions for installation are here. http://hortonworks.com/apache/zeppelin/#section_3
Zeppelin also comes installed with HDP sandbox (available here) which is a free single node VM running HDP.
Once you have the VM up and access the Zeppelin UI (at port 9995) you will see that it comes with a dozen demo notebooks (ranging from Spark, SparkSQL, Pyspark, Hive, Phoenix) which you can run through to get an idea of what's possible