What is a good book on GR? I have a good amount of experience with SR, and have spent a good deal of time researching GR, from Wikipedia, to PDF's, and youtube videos. I am moderately comfortable with Tensors, but a book that covers them in depth would be nice, not necessary, however. (I can look things up as I go if I run into problems with the maths). I started reading Øyvind Grøn's book on PDF, is anyone familiar with that? Ok, I guess they're lecture notes: https://www.google.com/?gws_rd=ssl#q=øyvind+grøn+GR+PDF It's been interesting, but I don't know if better material exists. I'm definitely not afraid to struggle, but I think I have a good enough conceptual understanding that if I do struggle, it will be in the maths. Thanks in advance!