The basis for your supporting arguments should be the material that has been covered in class and in the readings, and, if required, from outside sources.
The whole reason to take a course is to discover a framework for analyzing new phenomena (whether natural, social, literary, or artistic), and formal papers are an opportunity to demonstrate that you have learned enough to do such an analysis.
For topic papers, you are usually given a topic, or several to choose from, based on the course readings and discussion and are expected to make use of those resources (rather than outside ones) to write your paper.
Almost everything in this guide applies equally to both kinds of papers.
A good thesis should be debatable, specific, and concise.
The following is not a good thesis: * The history of the Soviet Union is very interesting and complex.
It takes one side of a possibly refutable argument.
One can imagine someone arguing that the history of the USSR indicates the problems of political totalitarianism and says nothing about economic planning.
I keep hearing from college professors that too many of their students don’t write well.
So here’s a primer written for college students on how to write an academic paper, though some of the advice would be useful for anybody writing anything.