How to use proxy in terminal

Department of Telelcom(India) just blocked some sites in India(for security reason: F****g Taliban). But, only Govt. based ISP don't allow us to access those sites. Other ISPs still have these sites working. One of those sites is GITHUB, I want to use GITHUB for pull, push repo & so many other things. How can I apply proxy to terminal(just like firefox or some browser). So, that I can access GitHub from terminal. Please explain in simple steps and explain each part for the same, I don't wanna blindly follow like an idiot. Thanks.

I saw this link for doing that in Linux but I guess Unix is little different from Linux.