With so much JSON being flung around from various APIs, jq has become a really helpful tool. Simon Willison mentioned two jq references that I had not seen before.
jqTerm is a playground site where you can paste in JSON, experiment with different jq queries, and immediately see the result.
jq recipes is a page from Remy Sharp that lists various uses of jq. Each one has a demo link back to jqterm.com. This is great for getting ideas on what you can do with jq.