There is also a nice small book by Paul Dirac https://books.google.ru/books?id=Jtu-n8AzJhMC

Unlike other texts, it derives everything through embedding of the space-time manifold to a high-dimensional Euclidian space. It means that although it lacks some generality, the curvature and covariant differentiation become somewhat more intuitive and the calculations might feel easier to follow for those who are studying the subject for the first time and are not familiar with differential geometry.