In 1964, Richard Feynman gave a series of seven, hour-long lectures at Cornell University that have gone down in history as a wonderfully accessible introduction to physics. Now, you can read them online for free.
In fact, the series of lectures spawned what became the best-selling series of physics books ever, which shifted over 1.5 million copies. But now the California Institute of Technology has finished publishing the original lectures in a free, HTML5-based viewer that can be read on any device. They cover the basics on pretty much all of physics you really need to know: mechanics, radiation, heat, matter, electromagnetism and quantum mechanics. Well worth a look, especially if you're spending a lazy Labor Day afternoon reading. [California Institute of Technology via Slashdot]