I second the no jeans idea. Well-fitting dark trousers are always a good option. The blouse and sweater idea sound good, too. Wearing jeans right off the bat may signal that you don't take the job seriously on a professional level, even though you will be wearing jeans every day (it may be safer just to stick to regular trousers). It's always better to be more conservative (think: safe bet, as opposed to: fashion conscious) in interview situations. And, of course, it's a great idea to carry a Coach bag. Maybe with a cute fob.
Good luck!
Good luck!