Riptano is going to be in Denver next Friday (Sept 10) for a full-day Cassandra training (taught by yours truly). The training is broken into two parts: the first covers application design and modeling in Cassandra, with exercises using the Pycassa library; the second covers operations, troubleshooting, and performance tuning.
For more details or to register for the training, see http://www.eventbrite.com/event/756085472 -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of Riptano, the source for professional Cassandra support http://riptano.com