Ask HN: How did you learn Apache Cassandra?

Hello,

My background: I've been programming for money for the last ten years using most of the popular programming languages. I have a CS degree from a small school. I have worked on embedded systems, desktop applications, front- and back-end server code.

I'm looking for helpful resources on learning Apache Cassandra? Is/was there a specific site or book or tutorial that was really helpful?

Outside of CS theory, what topics did you wish you knew before you started working with Cassandra?

Is there a project you'd recommend tackling for learning Cassandra?