Black Holes
Coursera
University of Alberta's introductory astronomy course, using black holes as the through-line for light, gravity, relativity, quantum physics, and stellar evolution. Finishing it, you can explain event horizons, Hawking radiation, and gravitational lensing in plain language.
More resources on Black Holes & Gravitational Waves
Event Horizon Telescope
Official site of the global VLBI array that produced the first images of the M87 and Sagittarius A* black holes. Carries press releases, published results, telescope details, and data releases from the collaboration.
blackholes.org
Blackholes.org is an educational resource that explains black holes and gravitational waves in accessible language, featuring diagrams, tutorials, and articles on concepts like event horizons, accretion disks, and recent discoveries in the field.
Gravity's Fatal Attraction
Non-technical account of black hole astrophysics by two working theorists, covering stellar-mass and supermassive holes, accretion discs, jets, and quasars. Readers come away understanding the observational evidence astronomers use to infer black holes exist.
Gravitational Waves
Graduate-level second volume of Maggiore's treatise, treating gravitational-wave sources: compact binary coalescence, supernovae, pulsars, and stochastic cosmological backgrounds. Requires general relativity and field theory; prepares readers to follow LIGO-Virgo detection papers and source-modelling literature.
gwcenter.icrr.u-tokyo.ac.jp
The Gravitational Wave Center at the University of Tokyo's Institute for Cosmic Ray Research offers educational resources and up-to-date information on gravitational waves and black holes. It features explanations of detectors (like KAGRA), lectures and seminars, research news, and data/outreach materials.