Yes, the red book is a must (along with the blue one, the Reference Manual), but if you are jumping in (which I believe is your case) I would suggest buying also another one that leads you in your first steps. The one that I used time ago for that purpose was written in german, so I am not going to mention it. Recently I got in touch with the lite version of OpenGL, OpenGL ES through the book "Mobile 3D Graphics". It is excellent, but it is just for OpenGL ES. Amazon.com surely has the answer for you.