I understand that you're suppose to understand both sides of an argument but be able to promote one side to refute your own.
I'm just not sure how to start off by defining the topic.
This is such a great question! Thanks for participating. I think a lot of people will benefit from looking at this thread.
The way you used the word refute seems wrong. You are supposed to refute the counter-argument. Another great way to understand this principle is to google around about a "Rogerian Argument."
It is okay to cite something in the first paragraph, although I think I once had a teacher that said we should not. But he was wrong! :-)
Anyway, do this:
Write a paragraph about an interesting article that you enjoy.
Repeat that until you have 5 paragraphs about 5 different articles, and in each paragraph talk about the article's topic by discussing it from YOUR point of view.
After writing 5 paragraphs, go back to the beginning and write an intro paragraph.
See what I mean? Write the intro last!! Well, write both the intro paragraph and the conclusion paragraph last. Write the body paragraphs first while you read interesting articles!