Easiest way for me to learn Elasticsearch was through queries generated by Kibana [1] and playing with them inside Sense [2]. Kibana relies on Facets, version elasticsearch 1.0 introduces Aggregations, I would suggest using aggregations for your projects.
[1] https://github.com/elasticsearch/kibana
[2] https://chrome.google.com/webstore/detail/sense/doinijnbnggo...