Online video lectures is the greatest thing to have happened for me in the last few months. There are a lot of them available through MIT OCW; Yale has released some; IITs have put up very good lectures on youtube; and so on. This is a great hub that points to a lot of them. I have some pointers here. Many of them can be downloaded as well.
It’s always a great thing when an expert explains things in a clear manner. It’s also much more convenient than reading up and understanding. And it takes much less effort. Someone like me gets to learn and/or revise things by going through them. If I have to study on my own, I would keep postponing it forever!
For example, I understood how simple Newtonian physics is, if presented well, like Prof. Ramamurti Shankar from Yale does; or how intriguing the things that we simply assume are, like I felt when a prof pondered over the question of ‘what are real numbers at all’, in a lecture from IIT. It is also amazing the extent to which people can go to ensure that what they are presenting is absolutely clear. To experience this amazement, one has to watch Prof. Walter Lewin teach physics. He doesn’t just teach physics, he makes physics happen. He brings all kind of stuff to his lectures. Balls, springs, ropes, what have you. In a particular lecture on springs, SHM etc., he first records the period of a 5m long pendulum that has a 15kg ball. Then to show that the period of a pendulum is independent of the mass, he places himself on the metal ball, and swings, keeping himself as horizontal as possible. Then he notes the time, rushes to the board to write it below the one for the ball alone. He then yells, “Physics works!”
First Principles 