Relativity: Special and General Theory

Recommended

Guidry, M. (2019) Modern General Relativity: Black Holes, Gravitational Waves, and Cosmology; Cambridge university press

Really good introductory book. Especially the first few chapters introducing the idea of tensors are excellent.

Schutz, B. F. (2009) A First Course in General Relativity, 2nd ed.; Cambridge University Press.

It should not be the first book, but it's well-written and full of insights.

If I get time

Coleman, S. (2021) Sidney Coleman’s Lectures on Relativity, ; Griffiths, D. J., Derbes, D., Sohn, R. B., Eds.; Cambridge University Press