Internet links on Physics:

General (latest news, information about all fields of Physics)

• physics.org from Institute of Physics
• Physics World  from Institute of Physics
• Physics Central from the American Physical Society

Lectures, seminars

• MIT Opencourse
• edX courses
• The Open Academy
• Physics Lectures
• Lecture Notes on Physics

Experiments, simulations, etc. 

• University of Oregon Virtual Laboratory
• Visual Quantum Mechanics
• Physics 2000
• The Physics Classroom

Encyclopedic

• HyperPhysics
• Eric Weisstein's World of Physics
• Wolfram Mathworld

Special topics

• Inquiring Minds
• Imagine the Universe
• Scientific-American: Ask the Experts
• NASA
• Hubble Space Telescope
• The particle adventure
• Fermilabyrinth
• The Quark Net
• The SLAC Virtual Visitor
• Particle Properties
• U.S. Particle Physics Educations and Outreach
• Cambridge Relativity
• The official String Theory Web Site
• Superstrings