The Smithsonian consist of serveral museums; each museum you could spend an entire day viewing the collections. You will only have a few hours to visit everything. Without a plan your visit can be very overwhelming. My suggestion to you is to talk to your friends on the trip to decide what is important to each of you and then move quickly so that you can accomplish your goals. If you have any specific questions, about the Smithsonians you can let Mrs. Sandy or Ms. Addie know and we will help you.
Here is the link the all the new and upcoming exhibits at the Smithsonian: http://www.si.edu/visit/whatsnew/DEFAULT.ASP
The link to the Smithsonian is http://www.si.edu/