Guys I need some Advice on this one

My Brother is a student in SYDNEY and he wants to come see me here in USA for a couple of weeks. He is a student there.

What are the documents required by US Consulate ?

I kinda get overwhelmed when 5 different people told me 5 different stories. I know some of you guys have been there and done that. I need some Pro advice here.

I also heard that I need a sponsorship letter or some financial document. Please let me know if I need one and How do I write it, who do I address it for?

Sorry I sound naive but I have never done this before and I won't take my chance on this one.

Your advice will be appreciated......