I believe that to become a better photographer it is important to know the history of the medium. One must examine the pictures of the great photographers and the various movements etc. But how should one begin. An excellent starting point is Jeff Curto’s podcast on the History of Photography which is his college course lecture’s sound combined with the slides he shows during the class. You can even just listen on your ipod and look at the slides later. I highly recommend it, and it is the one course in my life I repeated that I didn’t have to.

http://photohistory.jeffcurto.com/

PS. You could also probably spend the rest of your life going to all the links he provides

PPS. The photo by Niepce on the right is attributed by some as the first photo