Had a couple of add...
Don't be afraid to ask questions, seeming like a know-it-all will not impress anyone. Also be willing to admit you don't know.
Ask for feedback, try to find a time where you can sit/meet w/your preceptor to get a feel of where you are at. Doing well?/not doing well? Where you can work to make your skills better.
Try to get in to see everything you can, this is a learning expereince, so learn!
Mind you, this is speaking from experience. Tonight is my last night of my preceptorship in the ER, so I'v been there in your shoes so the speak. Making people aware that you are around will get you all sorts of opportuniites as well, like being told there is a great case coming in, or that the doc is going to do something you've never seen before (like a dialysis catheter placement at the bedside), to enhance your learning.
Enjoy and good luck!
Tom