At some point in the hiring process, you will be asked for references. The HR department will contact those folks in order to obtain specific types of information - that may not be the same as information provided in your letters of reference. So, you may just want to wait until this happens.
Congratulations on your interview. I recommend that you be prepared with clean copies of your resume as well as anything else that would help illustrate how motivated, smart, and fabulous you are. This may include special projects you completed in school, participation in other activities that could relate to your job (leadership? delegation? organization? time management? persistence?). I know that it may sound corny, but I also encourage new grads to 'practice' responding to interview questions... get a family member to ask you some of them and help critique your answers. You want to come across as personable, articulate and highly qualified - practice makes perfect. Your job is to "sell" brand Mega86an! Convince them that you can meet their needs far better than any other candidate.
Best of Luck to you!