Examkrackers books. I really like this book. It has good (colored!!) illustrations and me what concepts I should understand and what is not quite important enough to memorize.
I also have Audio Osmosis, which accompanies each book chapter. I've heard the guys that voice the lecture are funny in a nerdy way.
My shoulder has been feeling less stiff and sore today...which is partly the reason why I made myself study. The only exception is on occasion, I will move or turn and the motion will pull on something in my shoulder, which makes me twitch. It doesn't really hurt, but it isn't pleasant either.