Personally my favorite breeder is Tim Bailey at www.baileyreptiles.com.
Other good breeders that you can look into include;
http://www.8ballpythons.com/
http://www.bhbreptiles.com/
http://www.newenglandreptile.com/
Make sure to also read the ball python caresheet! You'll need all the information you can get.
http://www.ball-pythons.net/modules....warticle&id=59