Afterall’s One Work series is a library of small books, each title focusing on a single artwork that has significantly shaped the way we understand art and its history.
https://www.afterall.org/books/one.work/
It is also an excellent repository of research, articles, and publications relating to contemporary art practice. https://www.afterall.org/articles/
Whitechapel/MIT’s Documents of Contemporary Art is a series of books each centered on a different theme pertinent to contemporary art theory. Each book comprises of selected writings on said theme from contemporary artists and academics. These works provide a good entry point to make you aware of contemporary issues, ideas, and perspectives that can be further explored.
https://mitpress.mit.edu/books/series/whitechapel-documents-contemporary-art
It is also well worth reading art magazines like Frieze (https://frieze.com), Art Monthly (http://www.artmonthly.co.uk), and e-flux (https://www.e-flux.com). There is a useful repository of moving image and sound art, called Ubuweb, at http://ubuweb.com/. The Tate Modern website also has links to articles and videos on contemporary art and artists: https://www.tate.org.uk/art.
