If you plan to visit the DC area, it's worth the effort to try and get a tour. Give yourself some time to email your local assembly reps. Usually their webpages will have a link to input your tour request dates. Try to give up to 6 months advance notice. I was able to secure a tour with only a month notice and it was a wonderful experience walking inside. No, you will not see a house full of super old relics or see President Obama waiting to greet you--the rooms have been redone in old timey style so while it is pretty to look it--it doesn't have the rich hostory you woud imagine them to have. The original painting of George Washington is still hanging and it was a treat to see--Dolly Madison saved it right before the British burned the White House in the War of 1812. The whole tour is full of eye candy and it's neat to walk through and say you've been inside Obama's pad ;)
Very cool place to visit...although Lincoln seems a lot smaller in person :-/ when You think about all the amazing historical events that took place on those steps--it brings an even greater admiration for the memorial. Try visiting after the sun goes down. Much of the tourists are gone and The low lights highlighting Lincoln and the lit-up view of the Washington Monument are very nice. The downstairs museum is open til about 11pm. The park Rangers are on premises until 11pm also.