which Pipelining architecture, should i use and how to distinguish them! Is there any specific architecture to pipelining that we must follow to perform "operand-forwarding" inorder to avoid its harzards? 

My tutor seem to have, there are different architecture. And he taught us 3 different, and i am not even sure how to know which one to use.
In computer architecture, there is absolutely nothing that you must do. There are always compromises, everything has advantages and disadvantages, and advantages and disadvantages change over time. 

If you learned about three different architectures to achieve the same goal, you first check how each architecture fits in with the overall design, and then you invent a fourth one that works better. Your tutor can only tell you how things were done in the past; you'll have to find yourself how things will be done in the future.