Caltech-JPL Association for Gravitational-Wave Research (CaJAGWR) seminars: videos and slides
Caltech LIGO seminars: videos and slides
Alan Weinstein's 2006 lectures on Gravitational Waves and LIGO: Lecture 1, Lecture 2, Lecture 3, Slides.
2005 SLAC Summer School:
"Gravitational Radiation" by Alessandra Buonanno: Lecture 1, Lecture 2;
"Gravitational Wave Interferometric Detectors" by Gabriela Gonzalez: Lecture
Penn State master list with links to slides