The initial Hiring process was by far the hardest part of the entire situation. From the start at the career fair, you have to really stand out and make a great impression. If your credentials (coming right out of college) aren't great, chances are you probably won't get picked. With that being said, I found that if the HR recruiter likes you, the work you've done, and you show obvious signs of leadership at the career fair, you've gotten through the hardest part in the process. I interviewed with HR twice, got a call back a couple of weeks later (grueling, but be patient) and went to HQ to interview with 2 senior managers. The trick is (everyone says this) be yourself. If you aren't comfortable with this, it will show, and your interview is probably going to be terrible. You were picked because of your character and abilities, don't change just to sound right at an interview.