Seriously, it's awesome. A masterpiece. Go see it. My one recommendation is that you see it in the IMAX. Also, if you're looking for complete authenticity then rent a space documentary. This is a movie so it has lots dramatic license. It's fiction folks, although director Alfonso Cuaron did consult with astronauts and NASA. According to some real-life astronauts 'Gravity' got a lot of things right and a few things wrong.
Here are a couple of reviews.