For the past however-many years, Artur Ekert has been teaching the masters course “Introduction to Quantum Information” at the University of Oxford. During this time, many versions of accompanying lecture notes have come and gone, with constant improvements and changes being made. The version that you will find on this website has been carefully edited by Tim Hosgood into a cohesive book, containing additional exercises and topics, and is available in both HTML and PDF formats.
Complementary to the lecture notes, there are also lecture videos covering the same topics (but in a slightly different order), which can be found on YouTube. These are embedded in the web version of the book, but can also be watched separately as a standalone series.
P. Kaye, R. Laflamme, and M. Mosca. An Introduction to Quantum Computing. Oxford University Press, 2007.
M. Nielsen and I. Chuang. Quantum Computation and Quantum Information. Cambridge University Press, 2000.
J. Preskill. Ph219/CS219 Lecture Notes.
S. Aaronson. Quantum Computing since Democritus. Cambridge University Press, 2013. (Complementary lecture notes also available).
Quantum Open Source Foundation. Learning Resources on Quantum Computing.