Here are some reviews of his debates with accompanying links:
http://commonsenseatheism.com/?p=392
The most well known debate he's been in is probably his debate with Christopher Hitchens:
http://www.youtube.com/watch?v=4KBx4vvlbZ8
Most of his debates are with atheists, where he debates in favor of a generic theism and the atheist takes the, well, atheist position. He also has debates with Muslims and debates over issues other than theism/atheism (existence of the resurrection, that kind of thing).
Here's a solid interview with him:
http://www.youtube.com/watch?v=V2NhBbD-NJ8
I would watch that before any of the debates.