I just copied a word at random (photograph) and plugged it into Google. As usual, there was the spammy links Google likes to throw at you, a Wikipedia entry, but further down the page an interesting link to The First Photograph, an online exhibition from the University of Texas at Austin.
To say I am constantly amazed at the depth and scope of the online experience produced by this august community of scholars - in a place such as Texas, no less - would be an understatement.
The exhibition begins with a discussion of one Joseph Nicéphore Niépce, who began experimenting with photography in 1813, according to the text. There's also a timeline, an exposition on the term "heliography" and exceptional illustrations and photos, nicely displayed.
That's what makes the web so wonderful. Even when you're not even looking for anything, you can learn.