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:

Whitewoods Chinchilla Ranch