Now that Barack Obama has been sworn in and the transition away from George W. Bush's rule is complete, whitehouse.gov also got a makeover.
You can read the new administration's agenda, check out his briefing room (which includes a blog, news on appoinments and exective orders), and of course learn about the history of the White House--though you, like the rest of the world, might want to skip over the last eight years of that one.