Silva Rhetoricae - one of the best resources of classical rethoric.
http://www.experiment.lv/rus/debate/ - site of Debate organization of Latvia. You can read rules of Internet-debates, speeches of the game between Latvia and Russia, summaries of judges...
http://www.soros.org/debate/ - debate page on the Gorge Soros site. Actually, it was the starting point of everything!
http://www.policy.com/ - very useful site for Policy Debates. Has a great amount of useful information.