This was from www.emazing.com:
Fighting Puppy Mills

You think the local breeder's running a puppy
mill--putting
cash ahead of the safety and health of the animals
he
breeds. What do you do? Ideally, visit the mill with
a
friend--that way you'll have two witnesses. Keep
your eyes
open as you tour the facility, noting kennel
conditions,
multiple breeds, and such. When you get home, make
some
notes so you don't forget anything. Then contact
your local
humane society and express your concerns. Hopefully,
they'll take action against the "breeder."