I am about to start my thesis and I have, let's say, just an introductory course of General Relativity as background and I would like to know which would be a good book as a reference so that I can get a stronger knowledge of General Relativity. All this taking into account that I will do my thesis on gravitational waves. Some had suggested me books like: Introduction to Einstein's General Relativity-D'Inverno Gravitation-Misner,...(I am very tempted to take this my principal reference but I don not know it would be a good idea.) Gravitation- Weinberg An introductory course ...- Shutz B.F Well these are my main options. I am thinking about taking Gravitation-Misner as my first reference and D'Inverno as my second reference. The other ones would be just as complements. Any advise is accepted, keep in mind that I am just a beginner on G.R.