Help with writing a DBQ essay?

I have been assigned to write a DBQ essay about the perspectives of imperialism of the imperialist power and the colonized people. I really am not sure of what I should write about. I don't know if I should write about the motives for imperialism for the perspective of the imperialist power, then write about the pros and cons of it to describe the perspective of the colonized people. I just overall unsure and I would be extremely thankful to whomever could give me some suggestions of what to write. Thanks in advance.