Virginia Tech
Virginia Polytechnic Institute: Greenhouse Dinosaur Extinction Theory
This comprehensive page discusses the Asteroid Impact vs. Volcano-Greenhouse dinosaur extinction debate. It was written by paleontologist, professor, and scientist Dr. Dewey McLean.
BBC
Bbc: Rise and Fall of the Dinosaurs
Several articles that trace the chronology of the dinosaur from the Triassic to the Cretaceous. Articles were written to accompany the BBC series, Walking with Dinosaurs.