Pet adoption can be very expensive, this is just to warm you up to pet ownership, as this is also an expensive undertaking.  Finding a breeder that you can trust is critical.  Never be afraid to ask questions, questions, questions!  and did I forget to mention....ask questions? 
A reputable breeder should ask you questions as well and if you are not willing to answer, perhaps you need to re-think adopting.

Check out the area where the puppy has been bred and raised for cleanliness. Never visit a breeder who is willing to show or turn over for adoption puppies that are too young (before 8-12 weeks).  A reputable breeder recognizes the dangers of  strangers visiting and handling very young puppies as they can become sick. This may mean the  breeder is more interested in other things rather than health of the puppies. 

Ask to see both parents and litter mates of the puppy you are considering.  Ask how many litters they have per year. Avoid any breeder who "always" has puppies.  Prior to deciding to take puppy home, sign a contract with the breeder regarding the animals health guarantee.  The written guarantee should outline a refund or return policy.  It should also state the responsibilities of the breeder should the puppy become ill or show signs of genetic defects at a later date.  Within 10 days (or preferably as soon as you drive off with puppy in hand), visit your veterinarian for a complete puppy wellness check.  If there are any health problems found, contact the breeder immediately.

Obtain from the breeder the vaccination and worming records.  Get the contact information of the veterinarian they used  Verify this information with their vet, make sure that this puppy has been seen, vaccinated, and there are no known genetic defects.  Don't be embarrassed to call the veterinarian for references regarding this breeder's puppies.

A breeder should be prepared and willing to take back a dog for any reason.  Make sure this is in your written contract. It should always be first and foremost in the breeder's mind that the puppies
have a good and loving home forever! 

These are just a few tips to help you get started on finding a good breeder.
Contact your veterinarian or local animal shelter for further assistance.