No one is completely objective or unbiased. Every researcher has a particular point of view, as does every outside source.
As you work through the research process, think carefully about your beliefs, assumptions, and potential biases. How might these things influence your interpretation of outside sources? How does your point of view affect whether you agree or disagree with a certain argument? You should try to be reasonably objective in your research, looking at multiple points of view, not just those sources that agree with what you already think. However, you should also be aware of your point of view and how it influences your thinking.
Likewise, you should look for the beliefs, assumptions, and biases that influence other points of view. And you should be wary of authors who do not acknowledge their own biases or the existence of other points of view.