Update README.md

Author: rustyrazorblade

README.md

@@ -13,3 +13,7 @@ You can build an executable via the following command:
 This will create a JAR with a bash wrapper in the `bin` directory that you can drop in your $PATH and run like a normal Linux/Mac executable.  
 
 CDM doesn't currently work on windows as it's dependent on bash and cqlsh.  There are plans to lift this restriction.
+
+## Install a dataset 
+
+Assuming you've put the `cdm` executable in your path, you should be able to run `cdm update` and see an updated list of datasets.  Run `cdm list` to see all the ones available.  `cdm install <name>` loads your data in your local cassandra cluster.  For instance, `cdm install movielens`.