Agility Podcasts
Non-Agility/Canine Podcasts
Bitey End of the Dog (great for over-stimulated dogs)
Agility Nerd (videos, articles, etc.)
Course Maps (from actual trials)
Control Unleashed (Leslie McDermott)
Jumping for A to Z (Catherine Zinc; 1996 but still awesome training)
Jumping Grid Workbook (Susan Salo)