Last week I had a challenge of making a API callout to Instagram from Salesforce and then parse the returned JSON content and the mapped the values to become a record for a custom object. Basically each media post and comments becomes a record in Salesforce.
First off you can start by reading this article
According to http://www.json.org:
To begin, what I have here is an API request for comments for a particular media or picture I have in Instagram.