Try to make it to Union Station, right near the Capital. Great place to eat, and look around. The National Stamp museum is located right across from Union Station too. Have fun while enjoying your free museums. When you first get on the Mall, you should go to the Smithsonian Castle. Inside is the crypt of James Smithson, who the great Smithsonian museums are named after. The Castle has a big display of the Mall and nearby buildings that will give you some better direction once you have arrived.