Create Yammer app using REST API JSON

Need help writing simple javascript code that gets messages from Yammer network, parses the data, then displays on web page. I have app id and security token already. I just don't know how to write the code to connect to Yammer, get data, then display write it to web page. I want to style the data using CSS (which I can handle). Possible knowledge of JSON and REST API essential which is documented on Yammer Developer website.