Need a short tutorial and examples with postman

I need a short tutorial, actually need example for getting started with postman. I already have postman installed on my desktop. Your tutorial should provide me examples of making/sending following http request configuration at user interface level for post, put, get.. for instance, with headers and json body etc etc Why I need this tutorial or examples? I need this tutorial to know the details of how http get/post are sent via the browser. Once I know how the browser is sending/post to webserver or server, this will help me in understanding the complete flow between browser as a client and the webserver.