@farhan
In my personal opinion,one can not merely rely on his previous knowledge. Your practice of writing is to polish your skills and without reading good material you can never be able to write comprehensively.
As for as your assignment is concerned,i would like to say first try to make your points(short notes)....means what you are going to discuss...This rough strategy will lead you while searching relevent material.Search search and search and grasp the central ideas from that material.Don't try ro copy and paste ,just read that material and after reading and searching and writing short points on a rough page give a short break to your mind.Then after an hour or two or even more than that .....start organize your idea.Make a rough draf again and start writing.
I hope it will work for you

Regards