Here are some sites I have found useful:
Internet Forums:
Chins and Quills - A chinchilla and hedgehog forum
Chin Station - A chinchilla only forum
Chins and Gliders - A chinchilla and sugar glider forum
Chinchilla Supplies:
Oxbow Hay Company - Quality food and Hay
American Pet Diner - Quality food and Hay
Ryerson Chinchilla Ranch - Supplier of Tradition feed and other products
Chinchilla Breeders: