"Each of the Apollo landing missions is chronicled in detail through pictures and stories. We've even embedded video footage from Spacecraft Films that covers the most well-known moments on the surface. There are also immersive lunar surface panoramas, composed of photos taken by the astronauts themselves, presented for the first time in a 3D Street View style interface," explains Google.
To see the Moon, you need a recent version of Google Earth: after installing the software, click on the planet button from the toolbar and select "Moon".