arXiv. Open access site where physicists communicate about their research. arXiv is an e-print service in the fields of physics, mathematics, non-linear science, computer science, quantitative biology, quantitative finance and statistics.
The physics classroom. Tutorials and modules, hosted by Compadre.
United States Geological Survey.
Jet Propulsion Laboratory (California Institute of Technology). JPL has 24 spacecraft and 10 instruments conducting active missions, including Curiosity exploring Mars.
Fuck Yeah Fluid Dynamics Are cats a fluid? What caused the Boston Molasses Flood?
Physics: The first science. by 
The Handy Physics Answer Book by 
Are We There Yet? The Search for a Theory of Everything by 
Knocking on Heaven's Door: how physics and scientific thinking illuminate the universe and the modern world. by 
The Illustrated a Brief History of Time by 
The Pendulum: A case study in physics. by 
Invitation to Contemporary Physics by 
Surely You're Joking, Mr. Feynman! : adventures of a curious character. by