You’d be surprised how many great free books and lectures can be found on the internet. And the great thing about that is that even such a complex subject as General Relativity can be self-studied by anyone. So here’s a list of useful resources for those with an interest in GR. It includes books, lectures and videos.
This highly recommended course on General Relativity by Leonard Susskind includes 10 lectures. The subjects covered include the equivalence principle, curved geometry, space-time geometry, introduction to tensors and all the other good stuff you need for the basics. There’s also a similar course by Susskind from 2009, but I personally found the newer course more informative and simpler-to-understand.
These lectures notes by Gerard’t Hooft introduce the basic concepts of GR. It includes a summary of Special Relativity, the equivalence principle, curved coordinates, Riemann curvature, Einstein’s law of gravity, Schwarzschild metric and so on.
These notes by Sean M. Carroll also introduce the basics of GR. However, the notes are much longer and thorough than the previous entry. In addition to Special Relativity and the basics of GR, cosmology is also introduced in these notes.
Here’s a book by Einstein himself introduces the ideas and the philosophy behind the two theories of relativity. It doesn’t involve much maths, but it’s a good choice for beginners to get familiar with the basic ideas of relativity.
Here we have a 24 page long overview of GR, giving the main laws, equations and ideas. Good for gaining a basic understanding what the subject is about.
This book by Hans Stephani gives a more technical overview of GR than the previous entries. Recommended for those looking for a more advanced treatment of the subject.
As one of the most popular textbooks on GR, First Course in General Relativity by Schutz introduces the subject in a beginner-friendly way. It starts off with special relativity and progresses towards more complex topics. Highly recommended for beginners.
Here’s an alternative to the lectures by Susskind. If you can ignore the Indian accent, it’s a decent course giving all the basics.
This document is an overview of the main ideas of GR with no math. Recommended for beginners.
A number of short lectures by Avi Rabinowitz, which give a great overview to the ideas of GR. Once again recommended for beginners.