This site is an effort between Google and astronomers from some of the largest observatories around the world to bring you a different view of the sky. To learn more about the project check out the About page here. I would also really suggest heading there before diving in because that page also lists the FAQ and I found the questions answered there to be very helpful.
After that you’re ready to dive right in!
If there is something specific you want to see like the Horseshoe Nebula or Orion’s Belt, just type it into the search field at the top of the page. The page will then jump to where that celestial body is in the sky.
If you just want to poke around the universe, you can use the categories at the bottom of the page. They are: Solar System, Constellations, Hubble Showcase, Backyard Astronomy, Chandra X Ray Showcase, GALEX Ultraviolet Showcase, Spitzer Infrared Showcase, and Earth & Sky Podcasts. When you click into the categories they offer you an array of things to check out, and when you’re ready to move on to the next category you can click Home (left side of the bottom bar) to return back to the category menu.
This is another really cool way to explore the night sky.