Yay for job interviews!
Having had MANY intership interviews prior to summer I am a pro now
Suits are good, but you should remember that it's summer time still and I personally just find a suit too stuffy for summer! No women in my office are wearing suits right now, cause it's just not really seasonal.
One good thing about being a girl is that you can look formal without wearing a suit. Wearing a great top and a skirt is ideal. I would recommend a high waisted skirt (it does not have to be a pencil skirt if you're not comfortable wearing something that tight) and a nice top. Something with a little ruffle or embellishment that's not too bulky!
Grr it won't let me post a link, but if you go to Banana Republic's website and click on the man men collection, the outfit in the middle is what I have in mind!
Good luck!