This is a great site for those who are interested in the history of photography. I've used some of it in the classroom when needed, but I got Mr. Leggat's permission first.
I think that some historical reference should be required reading for anyone serious about photography.
I have read only a fraction of this site. One of the things I found particularly interesting was the rift between Daguerre and Niepce (someone I hadn't even heard of until I read through parts of the site).
Anyway, here's the link: