Prehistory is my favorite of all the historical data out there. Particularly the age of dinosaurs. Really cool stuff: The Fossil Project, WitmerLAB at Ohio University, Prehistoric Reserve: Dinosaur Park Project, The Jurassic Foundation, Fossilguy and many others are great sources of information. Also, Steve Brusatte's book "The Rise and Fall of The Dinosaurs A New History of a Lost World" is absolutely amazing; highly recommend it.